Merge from origin/emacs-25

4af5981 Add a comment in generated refcards about the source
ef880a5 ; * etc/refcards/calccard.tex: Remove obsolete comment.
4887e7c js-mode: Fix indent problem after a regexp
e992ac0 Fix sluggish display of symbols in UTF-8 language environment
1fc101b Don't confuse how Texinfo outputs @var with the input
91aa5d1 * doc/lispref/display.texi (Scroll Bars): * doc/lispref/frame...
f758fcd * doc/emacs/cmdargs.texi (Initial Options): Copyedit for --da...
5b0cddd More fixes in copyright notices in etc/refcards/
f994c20 Update copyright text in refcards
9ad2ae7 Fix Outline command names
26c3554 Send text received by bracketed paste to process
db0b58d Correct the statement about programming modes always running ...
78aece4 Improve documentation of 'occur'
eb364fd Do call debugger on failed cl-assert
3ef4ee8 Avoid infloop in python
8da810f Don't refer to obsolete FEATURE-unload-hook
4f478ca Improve documentation of dabbrevs
7272e5d * lisp/chistory.el (list-command-history): Doc fix.  (Bug#24890)
89b7482 * lisp/simple.el (set-mark-command): Doc fix.  (Bug#24890)
3b199f7 Improve documentation of some Help commands
93d3a0e Fix documentation of yes-or-no prompts
af04919 Fix documentation of partial completion style
ed80184 Fix documentation of the mode line on emacsclient frames
e6be855 Fix description of 'C-z' in User manual
16f7007 Improve and clarify documentation of Outline Mode
31d93aa Add Emacs version number to nt/README.W32
0b6b815 Fix python-mode hideshow regexp
dc152c5 Modernize usage of 'macOS' in doc and comments
84c5343 Prefer comments /* like this */ in C code
bb61e50 * doc/lispref/loading.texi (Autoload): Better link (Bug#24845).
3ef86fd Clarify documentation of face attribute functions
de51d59 ; * nt/README.W32: Minor copyedits.
db436e9 Don't call debug on failed cl-assert

# Conflicts:
#	doc/emacs/cmdargs.texi
#	etc/NEWS
#	etc/PROBLEMS
#	lisp/auth-source.el
#	lisp/net/tramp-sh.el

128 files changed, 824 insertions, 594 deletions

diff --git a/INSTALL b/INSTALL
index bc859b2c13b..76fe87d058f 100644
--- a/INSTALL
+++ b/INSTALL
@@ -5,7 +5,7 @@ See the end of the file for license conditions.
 
 
 This file contains general information on building GNU Emacs.
-For more information specific to the MS-Windows, GNUstep/Mac OS X, and
+For more information specific to the MS-Windows, GNUstep/macOS, and
 MS-DOS ports, also read the files nt/INSTALL, nextstep/INSTALL, and
 msdos/INSTALL.  For information about building from a repository checkout
 (rather than a release), also read the file INSTALL.REPO.
@@ -208,7 +208,7 @@ corresponding command is 'yum-builddep emacs'.
 
 DETAILED BUILDING AND INSTALLATION:
 
-(This is for a Unix or Unix-like system.  For GNUstep and Mac OS X,
+(This is for a Unix or Unix-like system.  For GNUstep and macOS,
 see nextstep/INSTALL.  For non-ancient versions of MS Windows, see
 the file nt/INSTALL.  For MS-DOS and MS Windows 3.X, see msdos/INSTALL.)
 
diff --git a/Makefile.in b/Makefile.in
index 109583705fb..2351537c3bc 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -113,7 +113,7 @@ am__v_at_1 =
 
 # ==================== Where To Install Things ====================
 
-# Location to install Emacs.app under GNUstep / Mac OS X.
+# Location to install Emacs.app under GNUstep / macOS.
 # Later values may use these.
 ns_appbindir=@ns_appbindir@
 ns_appresdir=@ns_appresdir@
diff --git a/README b/README
index 941cdfc2716..2a69b306ad9 100644
--- a/README
+++ b/README
@@ -86,9 +86,8 @@ There are several subdirectories:
                 in Emacs Lisp manual.
 'msdos'     holds configuration files for compiling Emacs under MS-DOS.
 'nextstep'  holds instructions and some other files for compiling the
-            Nextstep port of Emacs, for GNUstep and Mac OS X Cocoa.
-'nt'        holds various command files and documentation files that pertain
-            to building and running Emacs on Windows 9X/ME/NT/2000/XP.
+            Nextstep port of Emacs, for GNUstep and macOS Cocoa.
+'nt'        holds code and documentation for building Emacs on MS-Windows.
 'test'      holds tests for various aspects of Emacs's functionality.
 
    Building Emacs on non-Posix platforms requires tools that aren't part
diff --git a/admin/CPP-DEFINES b/admin/CPP-DEFINES
index 5e6146b33d8..487c1501bb9 100644
--- a/admin/CPP-DEFINES
+++ b/admin/CPP-DEFINES
@@ -21,7 +21,7 @@ WINDOWSNT	Compiling the native MS-Windows (W32) port.
 __MINGW32__	Compiling the W32 port with the MinGW or MinGW-w64 ports of GCC.
 _MSC_VER	Compiling the W32 port with the Microsoft C compiler.
 MINGW_W64	Compiling the W32 port with the MinGW-w64 port of GCC.
-DARWIN_OS	Compiling on Mac OS X or pure Darwin (and using s/darwin.h).
+DARWIN_OS	Compiling on macOS or pure Darwin (and using s/darwin.h).
 SOLARIS2
 USG
 USG5_4
@@ -29,7 +29,7 @@ USG5_4
 ** Distinguishing GUIs **
 
 HAVE_NTGUI	Use the native W32 GUI for windows, frames, menus&scrollbars.
-HAVE_NS		Use the NeXT/OpenStep/Cocoa UI under Mac OS X or GNUstep.
+HAVE_NS		Use the NeXT/OpenStep/Cocoa UI under macOS or GNUstep.
 NS_IMPL_GNUSTEP	Compile support for GNUstep implementation of NS GUI API.
 NS_IMPL_COCOA	Compile support for Cocoa (Apple) implementation of NS GUI API.
 HAVE_X11	Compile support for the X11 GUI.
diff --git a/admin/admin.el b/admin/admin.el
index 4af1ff9003a..9f3b68e0bb9 100644
--- a/admin/admin.el
+++ b/admin/admin.el
@@ -109,6 +109,9 @@ Root must be the root of an Emacs source tree."
 		       (rx (and "AC_INIT" (1+ (not (in ?,)))
                                 ?, (0+ space)
                                 (submatch (1+ (in "0-9."))))))
+  (set-version-in-file root "nt/README.W32" version
+		       (rx (and "version" (1+ space)
+				(submatch (1+ (in "0-9."))))))
   ;; TODO: msdos could easily extract the version number from
   ;; configure.ac with sed, rather than duplicating the information.
   (set-version-in-file root "msdos/sed2v2.inp" version
diff --git a/configure.ac b/configure.ac
index d9f52e5b8ad..c9759e18a02 100644
--- a/configure.ac
+++ b/configure.ac
@@ -343,8 +343,8 @@ OPTION_DEFAULT_ON([toolkit-scroll-bars],[don't use Motif or Xaw3d scroll bars])
 OPTION_DEFAULT_ON([xaw3d],[don't use Xaw3d])
 OPTION_DEFAULT_ON([xim],[don't use X11 XIM])
 AC_ARG_WITH([ns],[AS_HELP_STRING([--with-ns],
-[use Nextstep (OS X Cocoa or GNUstep) windowing system.
-On by default on Mac OS X.])],[],[with_ns=maybe])
+[use Nextstep (macOS Cocoa or GNUstep) windowing system.
+On by default on macOS.])],[],[with_ns=maybe])
 OPTION_DEFAULT_OFF([w32], [use native MS Windows GUI in a Cygwin build])
 
 OPTION_DEFAULT_ON([gpm],[don't use -lgpm for mouse support on a GNU/Linux console])
@@ -608,7 +608,7 @@ case "${canonical}" in
     opsys=openbsd
   ;;
 
-  ## Apple Darwin / Mac OS X
+  ## Apple Darwin / macOS
   *-apple-darwin* )
     case "${canonical}" in
       *-apple-darwin[0-9].*) unported=yes ;;
@@ -1895,14 +1895,14 @@ Either fix this, or re-configure with the option '--without-ns'.])])
 
   macfont_file=""
   if test "${NS_IMPL_COCOA}" = "yes"; then
-    AC_MSG_CHECKING([for OSX 10.6 or newer])
+    AC_MSG_CHECKING([for Mac OS X 10.6 or newer])
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <AppKit/AppKit.h>],
                                      [
 #ifdef MAC_OS_X_VERSION_MAX_ALLOWED
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= 1060
  ; /* OK */
 #else
- error "OSX 10.6 or newer required";
+ error "Mac OS X 10.6 or newer required";
 #endif
 #endif
 		    ])],
@@ -1911,7 +1911,7 @@ Either fix this, or re-configure with the option '--without-ns'.])])
     AC_MSG_RESULT([$ns_osx_have_106])
 
     if test $ns_osx_have_106 = no; then
-       AC_MSG_ERROR([OSX 10.6 or newer is required]);
+       AC_MSG_ERROR([Mac OS X 10.6 or newer is required]);
     fi
   fi
 fi
@@ -3615,9 +3615,9 @@ AC_CHECK_HEADERS_ONCE(malloc/malloc.h)
 GNUSTEP_CFLAGS=
 ### Use NeXTstep API to implement GUI.
 if test "${HAVE_NS}" = "yes"; then
-  AC_DEFINE(HAVE_NS, 1, [Define to 1 if you are using the NeXTstep API, either GNUstep or Cocoa on Mac OS X.])
+  AC_DEFINE(HAVE_NS, 1, [Define to 1 if you are using the NeXTstep API, either GNUstep or Cocoa on macOS.])
   if test "${NS_IMPL_COCOA}" = "yes"; then
-    AC_DEFINE(NS_IMPL_COCOA, 1, [Define to 1 if you are using NS windowing under MacOS X.])
+    AC_DEFINE(NS_IMPL_COCOA, 1, [Define to 1 if you are using NS windowing under macOS.])
   fi
   if test "${NS_IMPL_GNUSTEP}" = "yes"; then
     AC_DEFINE(NS_IMPL_GNUSTEP, 1, [Define to 1 if you are using NS windowing under GNUstep.])
@@ -4732,9 +4732,9 @@ case $opsys in
     ;;
 
   darwin)
-    dnl Not __APPLE__, as this may not be defined on non-OSX Darwin.
+    dnl Not __APPLE__, as this may not be defined on non-macOS Darwin.
     dnl Not DARWIN, because Panther and lower CoreFoundation.h use DARWIN to
-    dnl distinguish OS X from pure Darwin.
+    dnl distinguish macOS from pure Darwin.
     AC_DEFINE(DARWIN_OS, [], [Define if the system is Darwin.])
     ;;
 
diff --git a/doc/emacs/abbrevs.texi b/doc/emacs/abbrevs.texi
index a1db34cf0ee..227fe6f7ee2 100644
--- a/doc/emacs/abbrevs.texi
+++ b/doc/emacs/abbrevs.texi
@@ -341,7 +341,7 @@ abbrev expansion happens only when you request it explicitly.
 @table @kbd
 @item M-/
 Expand the word in the buffer before point as a @dfn{dynamic abbrev},
-by searching in the buffer for words starting with that abbreviation
+by searching for words starting with that abbreviation
 (@code{dabbrev-expand}).
 
 @item C-M-/
@@ -361,14 +361,19 @@ The variable @code{dabbrev-limit}, if non-@code{nil}, specifies how far
 away in the buffer to search for an expansion.
 
 @vindex dabbrev-check-all-buffers
+@vindex dabbrev-check-other-buffers
   After scanning the current buffer, @kbd{M-/} normally searches other
-buffers, unless you have set @code{dabbrev-check-all-buffers} to
-@code{nil}.
+buffers.  The variables @code{dabbrev-check-all-buffers} and
+@code{dabbrev-check-other-buffers} can be used to determine which
+other buffers, if any, are searched.
 
+@vindex dabbrev-ignored-buffer-names
 @vindex dabbrev-ignored-buffer-regexps
-  For finer control over which buffers to scan, customize the variable
-@code{dabbrev-ignored-buffer-regexps}.  Its value is a list of regular
-expressions.  If a buffer's name matches any of these regular
+  For finer control over which buffers to scan, customize the
+variables @code{dabbrev-ignored-buffer-names} and
+@code{dabbrev-ignored-buffer-regexps}.  The value of the former is a
+list of buffer names to skip.  The value of the latter is a list of
+regular expressions; if a buffer's name matches any of these regular
 expressions, dynamic abbrev expansion skips that buffer.
 
   A negative argument to @kbd{M-/}, as in @kbd{C-u - M-/}, says to
diff --git a/doc/emacs/cmdargs.texi b/doc/emacs/cmdargs.texi
index 8d3d936b7b3..524cd8dd268 100644
--- a/doc/emacs/cmdargs.texi
+++ b/doc/emacs/cmdargs.texi
@@ -558,11 +558,11 @@ variables is not set, the category defaults to the value of the
 @env{LANG} is not set.  But if @env{LC_ALL} is specified, it overrides
 the settings of all the other locale environment variables.
 
-On MS-Windows and OS X, if @env{LANG} is not already set in the
+On MS-Windows and macOS, if @env{LANG} is not already set in the
 environment, Emacs sets it based on the system-wide default.  You can
 set this in the ``Regional Settings'' Control Panel on some versions
 of MS-Windows, and in the ``Language and Region'' System Preference on
-OS X.
+macOS.
 
 The value of the @env{LC_CTYPE} category is
 matched against entries in @code{locale-language-names},
diff --git a/doc/emacs/entering.texi b/doc/emacs/entering.texi
index 09331e80fb1..7f186cfafe5 100644
--- a/doc/emacs/entering.texi
+++ b/doc/emacs/entering.texi
@@ -100,7 +100,7 @@ display them initially.
 Kill Emacs (@code{save-buffers-kill-terminal}).
 @item C-z
 On a text terminal, suspend Emacs; on a graphical display,
-iconify (or ``minimize'') the selected frame (@code{suspend-emacs}).
+iconify (or ``minimize'') the selected frame (@code{suspend-frame}).
 @end table
 
 @kindex C-x C-c
diff --git a/doc/emacs/help.texi b/doc/emacs/help.texi
index 4b7b7fc6315..64da8907172 100644
--- a/doc/emacs/help.texi
+++ b/doc/emacs/help.texi
@@ -411,8 +411,10 @@ Follow a hyperlink that you click on.
 Show all documentation about the symbol at point
 (@code{help-follow-symbol}).
 @item C-c C-f
+@itemx r
 Go forward to the next help topic (@code{help-go-forward}).
 @item C-c C-b
+@itemx l
 Go back to the previous help topic (@code{help-go-back}).
 @end table
 
@@ -422,15 +424,18 @@ Go back to the previous help topic (@code{help-go-back}).
 @findex help-go-forward
 @kindex RET @r{(Help mode)}
 @kindex C-c C-b @r{(Help mode)}
+@kindex l @r{(Help mode)}
 @kindex C-c C-f @r{(Help mode)}
+@kindex r @r{(Help mode)}
   When a function name, variable name, or face name (@pxref{Faces})
 appears in the documentation in the help buffer, it is normally an
 underlined @dfn{hyperlink}.  To view the associated documentation,
 move point there and type @key{RET} (@code{help-follow}), or click on
 the hyperlink with @kbd{mouse-1} or @kbd{mouse-2}.  Doing so replaces
 the contents of the help buffer; to retrace your steps, type @kbd{C-c
-C-b} (@code{help-go-back}).  While retracing your steps, you can go
-forward by using @kbd{C-c C-b} (@code{help-go-forward}).
+C-b} or @kbd{l} (@code{help-go-back}).  While retracing your steps,
+you can go forward by using @kbd{C-c C-f} or @kbd{r}
+(@code{help-go-forward}).
 
 @cindex URL, viewing in help
 @cindex help, viewing web pages
@@ -556,7 +561,8 @@ commands that you are not familiar with, you can use @kbd{C-h k} or
   Each Emacs major mode typically redefines a few keys and makes other
 changes in how editing works.  @kbd{C-h m} (@code{describe-mode})
 displays documentation on the current major mode, which normally
-describes the commands and features that are changed in this mode.
+describes the commands and features that are changed in this mode, and
+also its key bindings.
 
 @kindex C-h b
 @findex describe-bindings
diff --git a/doc/emacs/macos.texi b/doc/emacs/macos.texi
index b0597dc2499..6e6520b60bc 100644
--- a/doc/emacs/macos.texi
+++ b/doc/emacs/macos.texi
@@ -3,19 +3,19 @@
 @c See file emacs.texi for copying conditions.
 @node Mac OS / GNUstep
 @appendix Emacs and Mac OS / GNUstep
-@cindex Mac OS X
+@cindex macOS
 @cindex Macintosh
 @cindex GNUstep
 
   This section describes the peculiarities of using Emacs built with
 the GNUstep libraries on GNU/Linux or other operating systems, or on
-Mac OS X with native window system support.  On Mac OS X, Emacs can be
+macOS with native window system support.  On macOS, Emacs can be
 built either without window system support, with X11, or with the
 Cocoa interface; this section only applies to the Cocoa build.  This
-does not support versions of Mac OS X earlier than 10.6.
+does not support versions before Mac OS X 10.6.
 
   For various historical and technical reasons, Emacs uses the term
-@samp{Nextstep} internally, instead of ``Cocoa'' or ``Mac OS X''; for
+@samp{Nextstep} internally, instead of ``Cocoa'' or ``macOS''; for
 instance, most of the commands and variables described in this section
 begin with @samp{ns-}, which is short for @samp{Nextstep}.  NeXTstep
 was an application interface released by NeXT Inc during the 1980s, of
@@ -84,7 +84,7 @@ set, which often causes the subprocesses it launches to behave differently than
 they would when launched from the shell.
 
 For the PATH and MANPATH variables, a system-wide method
-of setting PATH is recommended on Mac OS X, using the
+of setting PATH is recommended on macOS, using the
 @file{/etc/paths} files and the @file{/etc/paths.d} directory.
 
 @node Mac / GNUstep Customization
@@ -117,8 +117,8 @@ close the altered one.
 Useful in this context is the listing of all faces obtained by
 @kbd{M-x list-faces-display}.
 
-@cindex Core Text, on Mac OS X
-In Mac OS X, Emacs uses a Core Text based font backend
+@cindex Core Text, on macOS
+In macOS, Emacs uses a Core Text based font backend
 by default.  If you prefer the older font style, enter the following
 at the command-line before starting Emacs:
 
diff --git a/doc/emacs/mini.texi b/doc/emacs/mini.texi
index be4206cb60c..7c97e425713 100644
--- a/doc/emacs/mini.texi
+++ b/doc/emacs/mini.texi
@@ -469,8 +469,8 @@ separately.  (For example, when completing command names,
 @samp{em-l-m} completes to @samp{emacs-lisp-mode}.)
 
 Furthermore, a @samp{*} in the minibuffer text is treated as a
-@dfn{wildcard}---it matches any character at the corresponding
-position in the completion alternative.
+@dfn{wildcard}---it matches any string of characters at the
+corresponding position in the completion alternative.
 
 @item emacs22
 This completion style is similar to @code{basic}, except that it
@@ -788,8 +788,8 @@ File ‘foo.el’ exists; overwrite? (y or n)
 Because this query does not actually use the minibuffer, the usual
 minibuffer editing commands cannot be used.  However, you can perform
 some window scrolling operations while the query is active: @kbd{C-l}
-recenters the selected window; @kbd{M-v} (or @key{PageDown} or
-@key{next}) scrolls forward; @kbd{C-v} (or @key{PageUp}, or
+recenters the selected window; @kbd{C-v} (or @key{PageDown} or
+@key{next}) scrolls forward; @kbd{M-v} (or @key{PageUp}, or
 @key{prior}) scrolls backward; @kbd{C-M-v} scrolls forward in the next
 window; and @kbd{C-M-S-v} scrolls backward in the next window.  Typing
 @kbd{C-g} dismisses the query, and quits the command that issued it
@@ -811,5 +811,5 @@ Buffer foo.el modified; kill anyway? (yes or no)
 To answer, you must type @samp{yes} or @samp{no} into the minibuffer,
 followed by @key{RET}.  The minibuffer behaves as described in the
 previous sections; you can switch to another window with @kbd{C-x o},
-use the history commands @kbd{M-p} and @kbd{M-f}, etc.  Type @kbd{C-g}
+use the history commands @kbd{M-p} and @kbd{M-n}, etc.  Type @kbd{C-g}
 to quit the minibuffer and the querying command.
diff --git a/doc/emacs/modes.texi b/doc/emacs/modes.texi
index c1564e9299b..63e31ab568c 100644
--- a/doc/emacs/modes.texi
+++ b/doc/emacs/modes.texi
@@ -113,10 +113,13 @@ hook}, a customizable list of Lisp functions to run each time the mode
 is enabled in a buffer.  @xref{Hooks}, for more information about
 hooks.  Each mode hook is named after its major mode, e.g., Fortran
 mode has @code{fortran-mode-hook}.  Furthermore, all text-based major
-modes run @code{text-mode-hook}, and all programming language modes
-run @code{prog-mode-hook}, prior to running their own mode hooks.
-Hook functions can look at the value of the variable @code{major-mode}
-to see which mode is actually being entered.
+modes run @code{text-mode-hook}, and many programming language modes
+@footnote{More specifically, the modes which are ''derived'' from
+@code{prog-mode} (@pxref{Derived Modes,,, elisp, The Emacs Lisp
+Reference Manual}).} (including all those distributed with Emacs) run
+@code{prog-mode-hook}, prior to running their own mode hooks.  Hook
+functions can look at the value of the variable @code{major-mode} to
+see which mode is actually being entered.
 
   Mode hooks are commonly used to enable minor modes (@pxref{Minor
 Modes}).  For example, you can put the following lines in your init
diff --git a/doc/emacs/msdos.texi b/doc/emacs/msdos.texi
index a87561ccf18..2793bb944bc 100644
--- a/doc/emacs/msdos.texi
+++ b/doc/emacs/msdos.texi
@@ -366,7 +366,7 @@ Emulate @sc{gnu} systems; this is the default.  This sets
 Emulate Unix systems.  Like @code{GNU}, but sets
 @code{ls-lisp-verbosity} to @code{(links uid)}.
 @item MacOS
-Emulate MacOS@.  Sets @code{ls-lisp-ignore-case} to @code{t}, and
+Emulate macOS@.  Sets @code{ls-lisp-ignore-case} to @code{t}, and
 @code{ls-lisp-dirs-first} and @code{ls-lisp-verbosity} to @code{nil}.
 @item MS-Windows
 Emulate MS-Windows.  Sets @code{ls-lisp-ignore-case} and
diff --git a/doc/emacs/mule.texi b/doc/emacs/mule.texi
index e735343cc75..882d75f5e61 100644
--- a/doc/emacs/mule.texi
+++ b/doc/emacs/mule.texi
@@ -745,7 +745,7 @@ exactly what to do for end-of-line conversion:
 @item @dots{}-unix
 Don't do any end-of-line conversion; assume the file uses
 newline to separate lines.  (This is the convention normally used
-on Unix and GNU systems, and Mac OS X.)
+on Unix and GNU systems, and macOS.)
 
 @item @dots{}-dos
 Assume the file uses carriage-return linefeed to separate lines, and do
@@ -757,8 +757,8 @@ Emacs doesn't support directly.})
 
 @item @dots{}-mac
 Assume the file uses carriage-return to separate lines, and do the
-appropriate conversion.  (This was the convention used on the
-Macintosh system prior to OS X.)
+appropriate conversion.  (This was the convention used in Classic Mac
+OS.)
 @end table
 
   These variant coding systems are omitted from the
@@ -1393,7 +1393,7 @@ of @code{standard-fontset-spec}.  This fontset's name is
 @noindent
 or just @samp{fontset-standard} for short.
 
-  On GNUstep and Mac OS X, the standard fontset is created using the value of
+  On GNUstep and macOS, the standard fontset is created using the value of
 @code{ns-standard-fontset-spec}, and on MS Windows it is
 created using the value of @code{w32-standard-fontset-spec}.
 
diff --git a/doc/emacs/rmail.texi b/doc/emacs/rmail.texi
index a8cf5e4a512..84f1296484a 100644
--- a/doc/emacs/rmail.texi
+++ b/doc/emacs/rmail.texi
@@ -1425,7 +1425,7 @@ local mailbox.
 @end table
 
 @noindent
-@var{Proto} can be one of:
+@var{proto} can be one of:
 
 @table @code
 @item mbox
@@ -1434,12 +1434,12 @@ Usual Unix mailbox format.  In this case, neither @var{user} nor
 of the mailbox file, e.g., @code{mbox://var/spool/mail/smith}.
 
 @item mh
-A local mailbox in the @acronym{MH} format.  @var{User} and
-@var{pass} are not used.  @var{Host-or-file-name} denotes the name of
+A local mailbox in the @acronym{MH} format.  @var{user} and
+@var{pass} are not used.  @var{host-or-file-name} denotes the name of
 @acronym{MH} folder, e.g., @code{mh://Mail/inbox}.
 
 @item maildir
-A local mailbox in the @acronym{maildir} format.  @var{User} and
+A local mailbox in the @acronym{maildir} format.  @var{user} and
 @var{pass} are not used, and @var{host-or-file-name} denotes the name of
 @code{maildir} mailbox, e.g., @code{maildir://mail/inbox}.
 
@@ -1448,14 +1448,14 @@ Any local mailbox format.  Its actual format is detected automatically
 by @code{movemail}.
 
 @item pop
-A remote mailbox to be accessed via POP3 protocol.  @var{User}
+A remote mailbox to be accessed via POP3 protocol.  @var{user}
 specifies the remote user name to use, @var{pass} may be used to
 specify the user password, @var{host-or-file-name} is the name or IP
 address of the remote mail server to connect to; e.g.,
 @code{pop://smith:guessme@@remote.server.net}.
 
 @item imap
-A remote mailbox to be accessed via IMAP4 protocol.  @var{User}
+A remote mailbox to be accessed via IMAP4 protocol.  @var{user}
 specifies the remote user name to use, @var{pass} may be used to
 specify the user password, @var{host-or-file-name} is the name or IP
 address of the remote mail server to connect to;
diff --git a/doc/emacs/screen.texi b/doc/emacs/screen.texi
index 716575706cf..46ccca52aa8 100644
--- a/doc/emacs/screen.texi
+++ b/doc/emacs/screen.texi
@@ -216,6 +216,11 @@ changes to either a forward slash (@samp{/}) or @samp{(Mac)}.  On some
 systems, Emacs displays @samp{(Unix)} instead of the colon for files
 that use newline as the line separator.
 
+  On frames created for @command{emacsclient} (@pxref{Invoking
+emacsclient}), the next character is @samp{@@}.  This indication is
+typical for frames of an Emacs process running as a daemon
+(@pxref{Emacs Server}).
+
   The next element on the mode line is the string indicated by
 @var{ch}.  This shows two dashes (@samp{--}) if the buffer displayed
 in the window has the same contents as the corresponding file on the
@@ -225,7 +230,7 @@ shows @samp{%*} if the buffer is modified, and @samp{%%} otherwise.
 
   The character after @var{ch} is normally a dash (@samp{-}).
 However, if the default-directory for the current buffer is on a
-remote machine, @samp{@@} is displayed instead (@pxref{File Names}).
+remote machine (@pxref{File Names}), @samp{@@} is displayed instead.
 
   @var{fr} gives the selected frame name (@pxref{Frames}).  It appears
 only on text terminals.  The initial frame's name is @samp{F1}.
diff --git a/doc/emacs/search.texi b/doc/emacs/search.texi
index b41214df1ae..543d5470046 100644
--- a/doc/emacs/search.texi
+++ b/doc/emacs/search.texi
@@ -1714,15 +1714,21 @@ a multi-file incremental search is activated automatically.
 @cindex mode, Occur
 @cindex match (face name)
 @vindex list-matching-lines-default-context-lines
+@kindex M-s o
 @item M-x occur
+@itemx M-s o
 Prompt for a regexp, and display a list showing each line in the
-buffer that contains a match for it.  The text that matched is
-highlighted using the @code{match} face.  To limit the search to part
-of the buffer, narrow to that part (@pxref{Narrowing}).  A numeric
-argument @var{n} specifies that @var{n} lines of context are to be
-displayed before and after each matching line.  The default number of
-context lines is specified by the variable
-@code{list-matching-lines-default-context-lines}.
+buffer that contains a match for it.  If you type @kbd{M-n} at the
+prompt, you can reuse search strings from previous incremental
+searches.  The text that matched is highlighted using the @code{match}
+face.  To limit the search to part of the buffer, narrow to that part
+(@pxref{Narrowing}).  A numeric argument @var{n} specifies that
+@var{n} lines of context are to be displayed before and after each
+matching line.  The default number of context lines is specified by
+the variable @code{list-matching-lines-default-context-lines}.
+
+You can also run @kbd{M-s o} when an incremental search is active;
+this uses the current search string.
 
 @kindex RET @r{(Occur mode)}
 @kindex o @r{(Occur mode)}
@@ -1744,12 +1750,6 @@ mode.
 The command @kbd{M-x list-matching-lines} is a synonym for @kbd{M-x
 occur}.
 
-@kindex M-s o
-@item M-s o
-Run @code{occur} using the search string of the last incremental
-string search.  You can also run @kbd{M-s o} when an incremental
-search is active; this uses the current search string.
-
 @item M-x multi-occur
 This command is just like @code{occur}, except it is able to search
 through multiple buffers.  It asks you to specify the buffer names one
diff --git a/doc/emacs/text.texi b/doc/emacs/text.texi
index 4c6a1ffbdd2..6c513c9a607 100644
--- a/doc/emacs/text.texi
+++ b/doc/emacs/text.texi
@@ -1088,92 +1088,101 @@ header line.
 
 @table @kbd
 @item C-c C-c
-Make the current heading line's body invisible (@code{hide-entry}).
+Make the current heading line's body invisible
+(@code{outline-hide-entry}).
 @item C-c C-e
-Make the current heading line's body visible (@code{show-entry}).
+Make the current heading line's body visible
+(@code{outline-show-entry}).
 @item C-c C-d
 Make everything under the current heading invisible, not including the
-heading itself (@code{hide-subtree}).
+heading itself (@code{outline-hide-subtree}).
 @item C-c C-s
 Make everything under the current heading visible, including body,
-subheadings, and their bodies (@code{show-subtree}).
+subheadings, and their bodies (@code{outline-show-subtree}).
 @item C-c C-l
 Make the body of the current heading line, and of all its subheadings,
-invisible (@code{hide-leaves}).
+invisible (@code{outline-hide-leaves}).
 @item C-c C-k
 Make all subheadings of the current heading line, at all levels,
-visible (@code{show-branches}).
+visible (@code{outline-show-branches}).
 @item C-c C-i
 Make immediate subheadings (one level down) of the current heading
-line visible (@code{show-children}).
+line visible (@code{outline-show-children}).
 @item C-c C-t
-Make all body lines in the buffer invisible (@code{hide-body}).
+Make all body lines in the buffer invisible
+(@code{outline-hide-body}).
 @item C-c C-a
-Make all lines in the buffer visible (@code{show-all}).
+Make all lines in the buffer visible (@code{outline-show-all}).
 @item C-c C-q
 Hide everything except the top @var{n} levels of heading lines
-(@code{hide-sublevels}).
+(@code{outline-hide-sublevels}).
 @item C-c C-o
 Hide everything except for the heading or body that point is in, plus
 the headings leading up from there to the top level of the outline
-(@code{hide-other}).
+(@code{outline-hide-other}).
 @end table
 
-@findex hide-entry
-@findex show-entry
+@findex outline-hide-entry
+@findex outline-show-entry
 @kindex C-c C-c @r{(Outline mode)}
 @kindex C-c C-e @r{(Outline mode)}
   The simplest of these commands are @kbd{C-c C-c}
-(@code{hide-entry}), which hides the body lines directly following the
-current heading line, and @kbd{C-c C-e} (@code{show-entry}), which
-reveals them.  Subheadings and their bodies are not affected.
+(@code{outline-hide-entry}), which hides the body lines directly
+following the current heading line, and @kbd{C-c C-e}
+(@code{outline-show-entry}), which reveals them.  Subheadings and
+their bodies are not affected.
 
-@findex hide-subtree
-@findex show-subtree
+@findex outline-hide-subtree
+@findex outline-show-subtree
 @kindex C-c C-s @r{(Outline mode)}
 @kindex C-c C-d @r{(Outline mode)}
 @cindex subtree (Outline mode)
-  The commands @kbd{C-c C-d} (@code{hide-subtree}) and @kbd{C-c C-s}
-(@code{show-subtree}) are more powerful.  They apply to the current
-heading line's @dfn{subtree}: its body, all of its subheadings, both
-direct and indirect, and all of their bodies.
-
-@findex hide-leaves
-@findex show-branches
-@findex show-children
+  The commands @kbd{C-c C-d} (@code{outline-hide-subtree}) and
+@kbd{C-c C-s} (@code{outline-show-subtree}) are more powerful.  They
+apply to the current heading line's @dfn{subtree}: its body, all of
+its subheadings, both direct and indirect, and all of their bodies.
+
+@findex outline-hide-leaves
+@findex outline-show-branches
+@findex outline-show-children
 @kindex C-c C-l @r{(Outline mode)}
 @kindex C-c C-k @r{(Outline mode)}
 @kindex C-c C-i @r{(Outline mode)}
-  The command @kbd{C-c C-l} (@code{hide-leaves}) hides the body of the
-current heading line as well as all the bodies in its subtree; the
-subheadings themselves are left visible.  The command @kbd{C-c C-k}
-(@code{show-branches}) reveals the subheadings, if they had previously
-been hidden (e.g., by @kbd{C-c C-d}).  The command @kbd{C-c C-i}
-(@code{show-children}) is a weaker version of this; it reveals just
-the direct subheadings, i.e., those one level down.
-
-@findex hide-other
+  The command @kbd{C-c C-l} (@code{outline-hide-leaves}) hides the
+body of the current heading line as well as all the bodies in its
+subtree; the subheadings themselves are left visible.  The command
+@kbd{C-c C-k} (@code{outline-show-branches}) reveals the subheadings,
+if they had previously been hidden (e.g., by @kbd{C-c C-d}).  The
+command @kbd{C-c C-i} (@code{outline-show-children}) is a weaker
+version of this; it reveals just the direct subheadings, i.e., those
+one level down.
+
+@findex outline-hide-other
 @kindex C-c C-o @r{(Outline mode)}
-  The command @kbd{C-c C-o} (@code{hide-other}) hides everything
-except the entry that point is in, plus its parents (the headers
-leading up from there to top level in the outline) and the top level
-headings.
-
-@findex hide-body
-@findex show-all
+  The command @kbd{C-c C-o} (@code{outline-hide-other}) hides
+everything except the entry that point is in, plus its parents (the
+headers leading up from there to top level in the outline) and the top
+level headings.  It also reveals body lines preceding the first
+heading in the buffer.
+
+@findex outline-hide-body
+@findex outline-show-all
 @kindex C-c C-t @r{(Outline mode)}
 @kindex C-c C-a @r{(Outline mode)}
 @findex hide-sublevels
 @kindex C-c C-q @r{(Outline mode)}
   The remaining commands affect the whole buffer.  @kbd{C-c C-t}
-(@code{hide-body}) makes all body lines invisible, so that you see
-just the outline structure (as a special exception, it will not hide
-lines at the top of the file, preceding the first header line, even
-though these are technically body lines).  @kbd{C-c C-a}
-(@code{show-all}) makes all lines visible.  @kbd{C-c C-q}
-(@code{hide-sublevels}) hides all but the top level headings; with a
-numeric argument @var{n}, it hides everything except the top @var{n}
-levels of heading lines.
+(@code{outline-hide-body}) makes all body lines invisible, so that you
+see just the outline structure (as a special exception, it will not
+hide lines at the top of the file, preceding the first header line,
+even though these are technically body lines).  @kbd{C-c C-a}
+(@code{outline-show-all}) makes all lines visible.  @kbd{C-c C-q}
+(@code{outline-hide-sublevels}) hides all but the top level headings
+at and above the level of the current heading line (defaulting to 1 if
+point is not on a heading); with a numeric argument @var{n}, it hides
+everything except the top @var{n} levels of heading lines.  Note that
+it completely reveals all the @var{n} top levels and the body lines
+before the first heading.
 
 @anchor{Outline Search}
 @findex reveal-mode
@@ -1219,8 +1228,9 @@ levels.
 
   Consider an Outline mode buffer with all the text and subheadings under
 level-1 headings hidden.  To look at what is hidden under one of these
-headings, you could use @kbd{C-c C-e} (@kbd{M-x show-entry}) to expose
-the body, or @kbd{C-c C-i} to expose the child (level-2) headings.
+headings, you could use @kbd{C-c C-e} (@kbd{M-x outline-show-entry})
+to expose the body, or @kbd{C-c C-i} to expose the child (level-2)
+headings.
 
 @kindex C-c C-z
 @findex foldout-zoom-subtree
@@ -1235,11 +1245,12 @@ in the mode line shows how deep you've gone.
 
   When zooming in on a heading, to see only the child subheadings specify
 a numeric argument: @kbd{C-u C-c C-z}.  The number of levels of children
-can be specified too (compare @kbd{M-x show-children}), e.g., @kbd{M-2
-C-c C-z} exposes two levels of child subheadings.  Alternatively, the
-body can be specified with a negative argument: @kbd{M-- C-c C-z}.  The
-whole subtree can be expanded, similarly to @kbd{C-c C-s} (@kbd{M-x
-show-subtree}), by specifying a zero argument: @kbd{M-0 C-c C-z}.
+can be specified too (compare @kbd{M-x outline-show-children}), e.g.,
+@w{@kbd{M-2 C-c C-z}} exposes two levels of child subheadings.
+Alternatively, the body can be specified with a negative argument:
+@w{@kbd{M-- C-c C-z}}.  The whole subtree can be expanded, similarly to
+@kbd{C-c C-s} (@kbd{M-x outline-show-subtree}), by specifying a zero
+argument: @w{@kbd{M-0 C-c C-z}}.
 
   While you're zoomed in, you can still use Outline mode's exposure and
 hiding functions without disturbing Foldout.  Also, since the buffer is
@@ -1256,8 +1267,8 @@ argument exits that many levels of folds.  Specifying a zero argument
 exits all folds.
 
   To cancel the narrowing of a fold without hiding the text and
-subheadings, specify a negative argument.  For example, @kbd{M--2 C-c
-C-x} exits two folds and leaves the text and subheadings exposed.
+subheadings, specify a negative argument.  For example, @w{@kbd{M--2 C-c
+C-x}} exits two folds and leaves the text and subheadings exposed.
 
   Foldout mode also provides mouse commands for entering and exiting
 folds, and for showing and hiding text:
diff --git a/doc/lispref/control.texi b/doc/lispref/control.texi
index 0c0827909a3..947c54f9c35 100644
--- a/doc/lispref/control.texi
+++ b/doc/lispref/control.texi
@@ -368,7 +368,7 @@ UPattern.  For example:
 @item (app @var{function} @var{upattern})
 Matches if @var{function} applied to the value being matched returns a
 value that matches @var{upattern}.  This is like the @code{pred}
-UPattern, except that it tests the result against @var{UPattern},
+UPattern, except that it tests the result against @var{upattern},
 rather than against a boolean truth value.  The @var{function} call can
 use one of the forms described below.
 @item (or @var{upattern1} @var{upattern2}@dots{})
diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index d050738d80f..851baa31f30 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -2548,7 +2548,7 @@ modifying the attributes of a named face.
 This function returns the value of the @var{attribute} attribute for
 @var{face} on @var{frame}.
 
-If @var{frame} is @code{nil}, that means the selected frame
+If @var{frame} is omitted or @code{nil}, that means the selected frame
 (@pxref{Input Focus}).  If @var{frame} is @code{t}, this function
 returns the value of the specified attribute for newly-created frames
 (this is normally @code{unspecified}, unless you have specified some
@@ -2644,8 +2644,8 @@ created frames.
 
   The following commands and functions mostly provide compatibility
 with old versions of Emacs.  They work by calling
-@code{set-face-attribute}.  Values of @code{t} and @code{nil} for
-their @var{frame} argument are handled just like
+@code{set-face-attribute}.  Values of @code{t} and @code{nil} (or
+omitted) for their @var{frame} argument are handled just like
 @code{set-face-attribute} and @code{face-attribute}.  The commands
 read their arguments using the minibuffer, if called interactively.
 
@@ -2714,7 +2714,8 @@ name used for @var{character}.
 @defun face-foreground face &optional frame inherit
 @defunx face-background face &optional frame inherit
 These functions return the foreground color (or background color,
-respectively) of face @var{face}, as a string.
+respectively) of face @var{face}, as a string.  If the color is
+unspecified, they return @code{nil}.
 @end defun
 
 @defun face-stipple face &optional frame inherit
@@ -4178,12 +4179,12 @@ bar.)  @var{horizontal-type} is either @code{bottom} or @code{nil}
 (which means no horizontal scroll bar).
 @end defun
 
-@defun frame-scroll-bar-width &optional Lisp_Object &optional frame
+@defun frame-scroll-bar-width &optional frame
 This function returns the width of vertical scroll bars of @var{frame}
 in pixels.
 @end defun
 
-@defun frame-scroll-bar-height &optional Lisp_Object &optional frame
+@defun frame-scroll-bar-height &optional frame
 This function returns the height of horizontal scroll bars of
 @var{frame} in pixels.
 @end defun
@@ -7155,7 +7156,7 @@ Emacs is displaying the frame using X.
 Emacs is displaying the frame using native MS-Windows GUI.
 @item ns
 Emacs is displaying the frame using the Nextstep interface (used on
-GNUstep and Mac OS X).
+GNUstep and macOS).
 @item pc
 Emacs is displaying the frame using MS-DOS direct screen writes.
 @item nil
diff --git a/doc/lispref/frames.texi b/doc/lispref/frames.texi
index 90f8e3501b2..dc1c524653d 100644
--- a/doc/lispref/frames.texi
+++ b/doc/lispref/frames.texi
@@ -764,7 +764,7 @@ its size using the @code{height} and @code{width} parameters
 with sizes and positions.  For all of these functions the argument
 @var{frame} must denote a live frame and defaults to the selected frame.
 
-@defun frame-position &optional Lisp_Object &optional frame
+@defun frame-position &optional frame
 This function returns the outer position (@pxref{Frame Layout}) of
 @var{frame} in pixels.  The value is a cons giving the coordinates of
 the top left corner of the outer frame of @var{frame} relative to an
@@ -772,9 +772,9 @@ origin at the position (0, 0) of the frame's display.  On a text
 terminal frame both values are zero.
 @end defun
 
-@defun set-frame-position frame X Y
-This function sets the outer frame position of @var{frame} to @var{X}
-and @var{Y}.  The latter arguments specify pixels and normally count
+@defun set-frame-position frame x y
+This function sets the outer frame position of @var{frame} to @var{x}
+and @var{y}.  The latter arguments specify pixels and normally count
 from an origin at the position (0, 0) of @var{frame}'s display.
 
 A negative parameter value positions the right edge of the outer frame
diff --git a/doc/lispref/loading.texi b/doc/lispref/loading.texi
index a73ae596e0d..44ce719bc1f 100644
--- a/doc/lispref/loading.texi
+++ b/doc/lispref/loading.texi
@@ -610,8 +610,8 @@ and @code{define-global-minor-mode}.
 
 @item Other definition types:
 @code{defcustom}, @code{defgroup}, @code{defclass}
-(@pxref{Top,EIEIO,,eieio,EIEIO}), and @code{define-skeleton} (see the
-commentary in @file{skeleton.el}).
+(@pxref{Top,EIEIO,,eieio,EIEIO}), and @code{define-skeleton}
+(@pxref{Top,Autotyping,,autotype,Autotyping}).
 @end table
 
   You can also use a magic comment to execute a form at build time
diff --git a/doc/lispref/nonascii.texi b/doc/lispref/nonascii.texi
index fd2ce3248fd..9f805c2c1d9 100644
--- a/doc/lispref/nonascii.texi
+++ b/doc/lispref/nonascii.texi
@@ -1049,8 +1049,7 @@ Unix convention, used on GNU and Unix systems, is to use the linefeed
 character (also called newline).  The DOS convention, used on
 MS-Windows and MS-DOS systems, is to use a carriage-return and a
 linefeed at the end of a line.  The Mac convention is to use just
-carriage-return.  (This was the convention used on the Macintosh
-system prior to OS X.)
+carriage-return.  (This was the convention used in Classic Mac OS.)
 
 @cindex base coding system
 @cindex variant coding system
diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index 3312705e167..903bad3b9c5 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -891,7 +891,7 @@ Berkeley BSD and its variants.
 Cygwin, a Posix layer on top of MS-Windows.
 
 @item darwin
-Darwin (Mac OS X).
+Darwin (macOS).
 
 @item gnu
 The GNU system (using the GNU kernel, which consists of the HURD and Mach).
diff --git a/doc/lispref/processes.texi b/doc/lispref/processes.texi
index 87c0b5c7687..21e1429f59d 100644
--- a/doc/lispref/processes.texi
+++ b/doc/lispref/processes.texi
@@ -648,7 +648,7 @@ I/O, file-name-coding-system}).
 If @var{coding} is @code{nil}, the default rules for finding the
 coding system will apply.  @xref{Default Coding Systems}.
 
-@item :connection-type @var{TYPE}
+@item :connection-type @var{type}
 Initialize the type of device used to communicate with the subprocess.
 Possible values are @code{pty} to use a pty, @code{pipe} to use a
 pipe, or @code{nil} to use the default derived from the value of the
diff --git a/doc/lispref/text.texi b/doc/lispref/text.texi
index c6a3eb035ad..0da34d14f24 100644
--- a/doc/lispref/text.texi
+++ b/doc/lispref/text.texi
@@ -4666,7 +4666,7 @@ Return all nodes in @var{dom} that have IDs that match @var{match},
 which is a regular expression.
 
 @item dom-strings @var{dom}
-Return all strings in @var{DOM}.
+Return all strings in @var{dom}.
 
 @end table
 
diff --git a/doc/lispref/tips.texi b/doc/lispref/tips.texi
index a8589df031c..b45e68d0d56 100644
--- a/doc/lispref/tips.texi
+++ b/doc/lispref/tips.texi
@@ -165,10 +165,10 @@ follow the naming conventions for hooks.  @xref{Hooks}.
 @item
 @cindex unloading packages, preparing for
 If loading the file adds functions to hooks, define a function
-@code{@var{feature}-unload-hook}, where @var{feature} is the name of
-the feature the package provides, and make it undo any such changes.
-Using @code{unload-feature} to unload the file will run this function.
-@xref{Unloading}.
+@code{@var{feature}-unload-function}, where @var{feature} is the name
+of the feature the package provides, and make it undo any such
+changes.  Using @code{unload-feature} to unload the file will run this
+function.  @xref{Unloading}.
 
 @item
 It is a bad idea to define aliases for the Emacs primitives.  Normally
diff --git a/doc/lispref/windows.texi b/doc/lispref/windows.texi
index d66a9448e63..2823cc55214 100644
--- a/doc/lispref/windows.texi
+++ b/doc/lispref/windows.texi
@@ -557,7 +557,7 @@ time @code{window-size-change-functions} was run for the last time on
 @cindex pixel width of a window
 @cindex total pixel width of a window
 
-@defun window-pixel-width &optional Lisp_Object &optional window
+@defun window-pixel-width &optional window
 This function returns the width of window @var{window} in pixels.
 @var{window} must be a valid window and defaults to the selected one.
 
@@ -4469,14 +4469,14 @@ This function returns the pixel edges of @var{window}'s body.  Calling
 the origin of the display screen rather than that of the frame:
 
 @defun window-absolute-pixel-edges &optional window
-This function returns the pixel coordinates of @var{WINDOW} relative to
+This function returns the pixel coordinates of @var{window} relative to
 an origin at (0, 0) of the display of @var{window}'s frame.  Calling
 @code{(window-absolute-pixel-edges)} is equivalent to calling
 @code{(window-edges window nil t t)}, see above.
 @end defun
 
 @defun window-absolute-body-pixel-edges &optional window
-This function returns the pixel coordinates of @var{WINDOW}'s body
+This function returns the pixel coordinates of @var{window}'s body
 relative to an origin at (0, 0) of the display of @var{window}'s frame.
 Calling @code{(window-absolute-body-pixel-edges window)} is equivalent
 to calling @code{(window-edges window t t t)}, see above.
diff --git a/doc/misc/efaq.texi b/doc/misc/efaq.texi
index 72a90a1ff21..9efe0e73c5c 100644
--- a/doc/misc/efaq.texi
+++ b/doc/misc/efaq.texi
@@ -1206,7 +1206,7 @@ Emacs can be started as a daemon in the background.
 
 @cindex NeXTstep port
 @cindex GNUstep port
-@cindex Mac OS X Cocoa
+@cindex macOS Cocoa
 @item
 There is a new NeXTstep port of Emacs.  This supports GNUstep and Mac OS
 X (via the Cocoa libraries).  The Carbon port of Emacs, which supported
@@ -3341,7 +3341,7 @@ problem (@pxref{Reporting bugs}).
 * Emacs for MS-DOS::
 * Emacs for MS-Windows::
 * Emacs for GNUstep::
-* Emacs for Mac OS X::
+* Emacs for macOS::
 @end menu
 
 @node Finding Emacs on the Internet
@@ -3561,13 +3561,13 @@ For MS-DOS, @pxref{Emacs for MS-DOS}.
 Beginning with version 23.1, Emacs supports GNUstep natively.
 See the file @file{nextstep/INSTALL} in the distribution.
 
-@node Emacs for Mac OS X
-@section Where can I get Emacs for Mac OS X?
+@node Emacs for macOS
+@section Where can I get Emacs for macOS?
 @cindex Apple computers, Emacs for
 @cindex Macintosh, Emacs for
-@cindex Mac OS X, Emacs for
+@cindex macOS, Emacs for
 
-Beginning with version 22.1, Emacs supports Mac OS X natively.
+Beginning with version 22.1, Emacs supports macOS natively.
 See the file @file{nextstep/INSTALL} in the distribution.
 
 @c ------------------------------------------------------------
diff --git a/doc/misc/gnus.texi b/doc/misc/gnus.texi
index 2473d26cc15..c34dd7caf08 100644
--- a/doc/misc/gnus.texi
+++ b/doc/misc/gnus.texi
@@ -21522,7 +21522,7 @@ bound to mairix searches and are automatically updated.
 Mairix is a tool for indexing and searching words in locally stored
 mail.  It was written by Richard Curnow and is licensed under the
 GPL@.  Mairix comes with most popular GNU/Linux distributions, but it also
-runs under Windows (with cygwin), Mac OS X and Solaris.  The homepage can
+runs under Windows (with cygwin), macOS and Solaris.  The homepage can
 be found at
 @uref{http://www.rpcurnow.force9.co.uk/mairix/index.html}
 
diff --git a/doc/misc/idlwave.texi b/doc/misc/idlwave.texi
index 26c81d65948..32b33641656 100644
--- a/doc/misc/idlwave.texi
+++ b/doc/misc/idlwave.texi
@@ -75,7 +75,7 @@ Interactive Data Language (IDL), and running IDL as an inferior shell.
 * Sources of Routine Info::     How does IDLWAVE know about routine XYZ
 * HTML Help Browser Tips::
 * Configuration Examples::      The user is king
-* Windows and MacOS::           What still works, and how
+* Windows and macOS::           What still works, and how
 * Troubleshooting::             When good computers turn bad
 * GNU Free Documentation License:: The license for this documentation.
 * Index::                       Fast access
@@ -2372,7 +2372,7 @@ Normal hook.  Executed when @file{idlwave.el} is loaded.
 @cindex Subprocess of Emacs, IDL
 @cindex Comint, Emacs package
 @cindex Windows
-@cindex MacOS
+@cindex macOS
 
 The IDLWAVE shell is an Emacs major mode which permits running the IDL
 program as an inferior process of Emacs, and works closely with the
@@ -2382,7 +2382,7 @@ debug these programs.  The IDLWAVE shell is built on @file{comint}, an
 Emacs packages which handles the communication with the IDL program.
 Unfortunately, IDL for Windows does not have command-prompt versions and
 thus do not allow the interaction with Emacs, so the IDLWAVE shell
-currently only works under Unix and MacOSX.
+currently works under only Unix and macOS.
 
 @menu
 * Starting the Shell::          How to launch IDL as a subprocess
@@ -3533,14 +3533,14 @@ to locate library catalogs.
 @end defopt
 
 @defopt idlwave-library-path
-IDL library path for Windows and MacOS@.  Under Unix/MacOSX, will be
+IDL library path for Windows and macOS@.  Under Unix/macOS, will be
 obtained from the Shell when run.
 @end defopt
 
 @defopt idlwave-system-directory
-The IDL system directory for Windows and MacOS@.  Also needed for
+The IDL system directory for Windows and macOS@.  Also needed for
 locating HTML help and the IDL Assistant for IDL v6.2 and later.  Under
-Unix/MacOSX, will be obtained from the Shell and recorded, if run.
+Unix/macOS, will be obtained from the Shell and recorded, if run.
 @end defopt
 
 @defopt idlwave-config-directory (@file{~/.emacs.d/idlwave})
@@ -3626,7 +3626,7 @@ performance is a problem and/or the catalogs are not needed.
 @cindex User catalog
 @cindex IDL library routine info
 @cindex Windows
-@cindex MacOS
+@cindex macOS
 @cindex IDL variable @code{!DIR}
 @cindex @code{!DIR}, IDL variable
 
@@ -3651,7 +3651,7 @@ catalog must be rescanned to update it.  Creating the user catalog is
 also much slower than scanning library catalogs.
 
 You can scan any of the directories on the currently known path.  Under
-Windows and MacOS (not OSX), you need to specify the IDL search path in
+Windows, you need to specify the IDL search path in
 the variable @code{idlwave-library-path}, and the location of the IDL
 directory (the value of the @code{!DIR} system variable) in the variable
 @code{idlwave-system-directory}, like this@footnote{The initial @samp{+}
@@ -3742,10 +3742,9 @@ files.  Therefore, such local files should not be installed inside the
 many other reasons.
 
 @cindex Windows
-@cindex MacOS
 @cindex IDL variable @code{!DIR}
 @cindex @code{!DIR}, IDL variable
-Users of Windows and MacOS (not X) also must set the variable
+Users of Windows also must set the variable
 @code{idlwave-system-directory} to the value of the @code{!DIR} system
 variable in IDL@.  IDLWAVE appends @file{lib} to the value of this
 variable and assumes that all files found on that path are system
@@ -3822,7 +3821,7 @@ etc.).
 @noindent Individual platform recommendations:
 
 @itemize @bullet
-@item Unix/MacOSX: The @uref{http://www.w3m.org,@code{w3m}} browser
+@item Unix/macOS: The @uref{http://www.w3m.org,@code{w3m}} browser
 and its associated
 @uref{http://emacs-w3m.namazu.org/,@code{emacs-w3m}} emacs mode
 provide in-buffer browsing with image display, and excellent speed and
@@ -4020,18 +4019,17 @@ user is King!
 @html
 <A NAME="WINDOWS_MAC"></A>
 @end html
-@node Windows and MacOS
-@appendix Windows and MacOS
+@node Windows and macOS
+@appendix Windows and macOS
 @cindex Windows
-@cindex MacOS
-@cindex MacOSX
+@cindex macOS
 
 IDLWAVE was developed on a UNIX system.  However, thanks to the
 portability of Emacs, much of IDLWAVE does also work under different
-operating systems like Windows (with NTEmacs or NTXEmacs) or MacOS.
+operating systems like Windows (with NTEmacs or NTXEmacs).
 
 The only real problem is that there is no command-line version of IDL
-for Windows or MacOS(<=9) with which IDLWAVE can interact.  As a
+for Windows with which IDLWAVE can interact.  As a
 result, the IDLWAVE Shell does not work and you have to rely on IDLDE
 to run and debug your programs.  However, editing IDL source files
 with Emacs/IDLWAVE works with all bells and whistles, including
@@ -4112,10 +4110,10 @@ ensure @samp{idl} is on your @samp{$PATH}, or specify the full
 pathname to the idl program with the variable
 @code{idlwave-shell-explicit-file-name}.  Note that you may need to
 set your shell search path in two places when running Emacs as an Aqua
-application with MacOSX; see the next topic.
+application with macOS; see the next topic.
 
 @item @strong{IDLWAVE is disregarding my @samp{IDL_PATH} which I set
-under MacOSX}
+under macOS}
 
 If you run Emacs directly as an Aqua application, rather than from the
 console shell, the environment is set not from your usual shell
diff --git a/doc/misc/mairix-el.texi b/doc/misc/mairix-el.texi
index 8deead52dc6..69d3fc42277 100644
--- a/doc/misc/mairix-el.texi
+++ b/doc/misc/mairix-el.texi
@@ -68,7 +68,7 @@ database.
 Mairix is a tool for indexing and searching words in locally stored
 mail.  It was written by Richard Curnow and is licensed under the
 GPL@.  Mairix comes with most popular GNU/Linux distributions, but it also
-runs under Windows (with cygwin), Mac OS X and Solaris.  The homepage can
+runs under Windows (with cygwin), macOS and Solaris.  The homepage can
 be found at
 @uref{http://www.rpcurnow.force9.co.uk/mairix/index.html}
 
diff --git a/doc/misc/org.texi b/doc/misc/org.texi
index a5239acb59f..a6f9dbde7cb 100644
--- a/doc/misc/org.texi
+++ b/doc/misc/org.texi
@@ -6616,7 +6616,7 @@ applying it to another one.
 @vindex org-clock-idle-time
 By customizing the variable @code{org-clock-idle-time} to some integer, such
 as 10 or 15, Emacs can alert you when you get back to your computer after
-being idle for that many minutes@footnote{On computers using Mac OS X,
+being idle for that many minutes@footnote{On computers using macOS,
 idleness is based on actual user idleness, not just Emacs' idle time.  For
 X11, you can install a utility program @file{x11idle.c}, available in the
 @code{contrib/scripts} directory of the Org git distribution, or install the
diff --git a/doc/misc/tramp.texi b/doc/misc/tramp.texi
index 0e09cf7e7bb..955a13e477a 100644
--- a/doc/misc/tramp.texi
+++ b/doc/misc/tramp.texi
@@ -933,7 +933,7 @@ D-Bus, dbus}.
 @cindex afp method
 
 This method is for connecting to remote hosts with the Apple Filing
-Protocol for accessing files on Mac OS X volumes.  @value{tramp} access
+Protocol for accessing files on macOS volumes.  @value{tramp} access
 syntax requires a leading volume (share) name, for example:
 @file{@trampfn{afp,user@@host,/volume}}.
 
diff --git a/etc/DISTRIB b/etc/DISTRIB
index 7c0cd4cbaca..237e7f265f9 100644
--- a/etc/DISTRIB
+++ b/etc/DISTRIB
@@ -31,8 +31,8 @@ manuals, including the Emacs manual, are available from the FSF's
 online store at http://shop.fsf.org.
 
 Emacs has been run on GNU/Linux, FreeBSD, NetBSD, OpenBSD, and on many
-Unix systems, on a variety of types of cpu, as well as on MSDOS,
-Windows and MacOS.  See the file 'etc/MACHINES' in the Emacs
+Unix systems, on a variety of types of CPU, as well as on MS-DOS,
+MS-Windows and macOS.  See the file 'etc/MACHINES' in the Emacs
 distribution for a full list of machines that GNU Emacs has been tested
 on, with machine-specific installation notes and warnings.
 
diff --git a/etc/MACHINES b/etc/MACHINES
index 5562dc26035..15ac91772e0 100644
--- a/etc/MACHINES
+++ b/etc/MACHINES
@@ -64,9 +64,9 @@ the list at the end of this file.
   This was tested on a little-endian sh4 system (cpu type SH7751R) running
   Gentoo Linux 2008.0.
 
-** Mac OS X
+** macOS
 
-  Version 10.6 or newer.  PowerPC is not supported.
+  Mac OS X 10.6 or newer.  PowerPC is not supported.
   For installation instructions see the file nextstep/INSTALL.
 
 ** Microsoft Windows
diff --git a/etc/NEWS.22 b/etc/NEWS.22
index 1bc4967d6ab..5e414f18d64 100644
--- a/etc/NEWS.22
+++ b/etc/NEWS.22
@@ -262,7 +262,7 @@ item was added to the menu bar to make it easily accessible
 You no longer need to download a separate tarball in order to build
 Emacs with Leim.
 
-** Support for MacOS X was added.
+** Support for Mac OS X was added.
 See the files mac/README and mac/INSTALL for build instructions.
 
 ** Mac OS 9 port now uses the Carbon API by default.  You can also
@@ -3390,7 +3390,7 @@ obsolete; use `dframe-update-speed' instead.
 
 *** display-battery-mode replaces display-battery.
 
-*** battery.el now works on recent versions of OS X.
+*** battery.el now works on recent versions of Mac OS X.
 
 ** Games
 
diff --git a/etc/NEWS.24 b/etc/NEWS.24
index df2e11f08e7..08021f4ee04 100644
--- a/etc/NEWS.24
+++ b/etc/NEWS.24
@@ -84,7 +84,7 @@ It is no longer needed, as the crt*.o files are no longer linked specially.
 ** Directories passed to configure option `--enable-locallisppath' are
 no longer created during installation.
 
-** Emacs for Nextstep (Mac OS X, GNUstep) can be built with ImageMagick support.
+** Emacs for Nextstep (OS X, GNUstep) can be built with ImageMagick support.
 This requires pkg-config to be available at build time.
 
 
@@ -1559,7 +1559,7 @@ The previous binding, introduced in Emacs 24.1, was a mistake, because
 
 *** New input method `vietnamese-vni'.
 
-** Nextstep (GNUstep / Mac OS X) port
+** Nextstep (GNUstep / OS X) port
 
 *** Support for fullscreen and the frame parameter fullscreen.
 
@@ -2373,9 +2373,9 @@ Emacs now supports `mouse-highlight', help-echo (in the echo area), and
 ** On MS Windows, you can pass `--without-libxml2' to configure.bat to omit
 support for libxml2, even if its presence is detected.
 
-** On Mac OS X, the Nextstep port requires OS X 10.4 or later.
+** On OS X, the Nextstep port requires Mac OS X 10.4 or later.
 
-** On Mac OS X, configure no longer automatically adds the Fink "/sw"
+** On OS X, configure no longer automatically adds the Fink "/sw"
 directories to the search path.  You must add them yourself if you want them.
 
 
@@ -3833,7 +3833,7 @@ and also when HOME is set to C:\ by default.
 (It is only used internally in the Emacs C code.)
 
 ** Customize ns-auto-hide-menu-bar to have the menu-bar hidden, but
-reappear on mouse-over.  (Requires OS X 10.6 or later.)
+reappear on mouse-over.  (Requires Mac OS X 10.6 or later.)
 
 ** On Mac OS X, dragging a file into Emacs visits the file, like on
 other platforms, rather than inserting its contents into the buffer.
diff --git a/etc/NEWS.25 b/etc/NEWS.25
index a5bcb8dabdc..f6792431907 100644
--- a/etc/NEWS.25
+++ b/etc/NEWS.25
@@ -88,7 +88,7 @@ If gnustep-config is not available, the old heuristics are used.
 unless gfile is explicitly requested via --with-file-notification='gfile'.
 
 ** 'configure' detects the kqueue file notification library on *BSD
-and Mac OS X machines.
+and macOS machines.
 
 ** The configure option '--with-pkg-config-prog' has been removed.
 Use './configure PKG_CONFIG=/full/name/of/pkg-config' if you need to.
@@ -202,10 +202,10 @@ the 'network-security-level' variable.
 
 ** 'x-select-enable-clipboard' is renamed 'select-enable-clipboard'
 and 'x-select-enable-primary' is renamed 'select-enable-primary'.
-Additionally they both now apply to all systems (OSX, GNUstep, Windows, you
-name it), with the proviso that on some systems (e.g. Windows)
-'select-enable-primary' is ineffective since the system doesn't
-have the equivalent of a primary selection.
+Additionally they both now apply to all systems (macOS, GNUstep,
+MS-Windows, you name it), with the proviso that on some systems (e.g.,
+MS-Windows) 'select-enable-primary' is ineffective since the system
+doesn't have the equivalent of a primary selection.
 
 ** New option 'switch-to-buffer-in-dedicated-window' allows you to
 customize how 'switch-to-buffer' proceeds interactively when the
@@ -817,7 +817,7 @@ PLIST will contain a :peer element that has the output of
 
 ** Tramp
 
-*** New connection method "afp", which allows you to access Mac OS X
+*** New connection method "afp", which allows you to access macOS
 volumes via the Apple Filing Protocol.
 
 *** New connection method "nc", which allows you to access dumb
@@ -1076,7 +1076,7 @@ See <http://debbugs.gnu.org/22814>.
 
 ** File Notifications
 
-*** The kqueue library is integrated for *BSD and Mac OS X machines.
+*** The kqueue library is integrated for *BSD and macOS machines.
 
 *** The new event 'stopped' signals, that a file notification watch is
 not active any longer.
@@ -1743,19 +1743,19 @@ of Windows starting with Windows 9X.
 ** The byte counts in etags-generated TAGS files are now the same on
 MS-Windows as they are on other platforms.
 
-** On OS X, configure creates a Cocoa ("Nextstep") build by default.
+** On macOS, configure creates a Cocoa ("Nextstep") build by default.
 Pass '--without-ns' to configure to create an X11 build, the old default.
 
-** OS X 10.5 or older is no longer supported.
+** Mac OS X 10.5 or older is no longer supported.
 
-** OS X on PowerPC is no longer supported.
+** Mac OS X on PowerPC is no longer supported.
 
 ** New variable 'ns-use-fullscreen-animation' controls animation for
 non-native NS fullscreen.  The default is nil.  Set to t to enable
-animation when entering and leaving fullscreen.  For native OSX fullscreen
-this has no effect.
+animation when entering and leaving fullscreen.  For native macOS
+fullscreen this has no effect.
 
-** On the OS X Cocoa ("Nextstep") port, multicolor font (such as color
+** On the macOS Cocoa ("Nextstep") port, multicolor font (such as color
 emoji) display is disabled.  This feature was accidentally added when
 Emacs 24.4 included the new Core Text based font backend code that was
 originally implemented for a non-mainline port.  This will be enabled
diff --git a/etc/NEXTSTEP b/etc/NEXTSTEP
index ad2ab959e6d..60c49ad8c7e 100644
--- a/etc/NEXTSTEP
+++ b/etc/NEXTSTEP
@@ -3,8 +3,8 @@ See the end of the file for license conditions.
 
 This file contains information about GNU Emacs on "Nextstep" platforms.
 The Nextstep support code works on many POSIX systems (and possibly
-W32) using the GNUstep libraries, and on MacOS X systems using the
-Cocoa libraries.
+W32) using the GNUstep libraries, and on macOS systems using the Cocoa
+libraries.
 
 Background
 ----------
@@ -17,9 +17,9 @@ system in the late 1980's.  Later on, in collaboration with Sun, this
 API was published as a specification called OpenStep.  The GNUstep
 project started in the early 1990's to provide a free implementation
 of this API.  Later on, Apple bought NeXT (some would say "NeXT bought
-Apple") and made OpenStep the basis of OS X, calling the API "Cocoa".
-Since then, Cocoa has evolved beyond the OpenStep specification, and
-GNUstep has followed it.
+Apple") and made OpenStep the basis of Mac OS X, calling the API
+"Cocoa".  Since then, Cocoa has evolved beyond the OpenStep
+specification, and GNUstep has followed it.
 
 Thus, calling this port "OpenStep" is not technically accurate, and in
 the absence of any other determinant, we are using the term
@@ -30,8 +30,8 @@ begin with the letters "NS".
 (See http://en.wikipedia.org/wiki/Nextstep)
 
 This Emacs port was first released in the early 1990's on the NeXT
-computer, and was successively updated to OpenStep, Rhapsody, OS X,
-and then finally GNUstep, tracking GNU emacs core releases in the
+computer, and was successively updated to OpenStep, Rhapsody, Mac OS
+X, and then finally GNUstep, tracking GNU Emacs core releases in the
 meantime.
 
 
@@ -62,13 +62,13 @@ Release History
 
 1999/05/??	6.0b3		Scott Bender: "OS X Server", Emacs 20.3.
 
-2001/06/25	7.0		Ported to MacOS X (10.1) by Christophe de
+2001/06/25	7.0		Ported to Mac OS X (10.1) by Christophe de
 				Dinechin. Release based on Emacs 20.7. Hosting
 				moved to SourceForge.
 
 2002/01/03	7.0.1		Bug fixes.
 
-2002/08/27	7.0.2		Jaguar (OS X 10.2) support. Added an autoconf
+2002/08/27	7.0.2		Jaguar (Mac OS X 10.2) support. Added autoconf
 				option for sys_nerr being in stdio. Added
 				libncurses to the build libraries. Fixed a
 				problem with ns-alternate-is-meta. Changed the
@@ -76,7 +76,7 @@ Release History
 
 2004/10/07	8.0-pre1	Ported to GNUstep by Adrian Robert.
 
-2004/11/04	8.0-pre2	Restored functionality on OS X (menu code
+2004/11/04	8.0-pre2	Restored functionality on Mac OS X (menu code
 				cleanup).  Improved scrollbar handling and
 				paste from other applications.  File icons
 				obtained properly from NSWorkspace.  Dropped
@@ -116,7 +116,8 @@ Release History
 				and Planner go away.  Improved scrollbar
 				handling and rendering speed.  Color panel
 				and other bug fixes. mac-fix-env utility.
-				Font handling improvements (OS X 10.3, 10.4):
+				Font handling improvements (Mac OS X 10.3,
+				10.4):
 				- heed 'GSFontAntiAlias' default
 				- heed system antialiasing threshold
 				- added 'UseQuickdrawSmoothing' default to
@@ -150,8 +151,9 @@ Release History
 				handling improved.  Fixed some portability
 				problems on Tiger and Puma.
 
-2005/09/12	8.0		Bundled ispell on OS X.  Minor bug fixes and
-				stability improvements.  Compiles under gcc-4.
+2005/09/12	8.0		Bundled ispell on Mac OS X.  Minor bug fixes
+				and stability improvements.  Compiles under
+				gcc-4.
 
 2005/09/26	8.0.1		Correct clipped rendering for synthetic
 				italics. Include the info directory.
@@ -247,7 +249,7 @@ Christian Limpach
 Scott Bender
     OpenStep, Rhapsody ports
 Christophe de Dinechin
-    MacOS X port
+    macOS port
 Adrian Robert
     GNUstep port, update Emacs 20 -> 21+
 
diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 9d80139fa94..8d8c0c604a7 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -952,7 +952,7 @@ instead of requiring each Babel library one by one.
 - New option [[doc:org-gnus-no-server][org-gnus-no-server]] to start Gnus with =gnus-no-server=
 - Org is now distributed with =htmlize.el= version 1.43
 - ~org-drill.el~ has been updated to version 2.3.7
-- ~org-mac-iCal.el~ now supports MacOSX version up to 10.8
+- ~org-mac-iCal.el~ now supports OS X versions up to 10.8
 - Various improvements to ~org-contacts.el~ and =orgpan.el=
 
 ** Outside Org
diff --git a/etc/TODO b/etc/TODO
index 48c1654aa1f..84c1b6d8ffd 100644
--- a/etc/TODO
+++ b/etc/TODO
@@ -700,7 +700,7 @@ resize the frame.
 **** Support 'proced' (implement 'process-attributes')
 
 Unfortunately, a user-level process like Emacs does not have the
-privileges to get information about other processes under OS X.
+privileges to get information about other processes under macOS.
 
 There are other ways to do this:
 
@@ -711,7 +711,7 @@ There are other ways to do this:
  3) Ask the user to self-sign Emacs, if this feature is of interest.
 
 Anders Lindgren <andlind@gmail.com> has implemented
-'process-attributes' for OS X, which currently only work when
+'process-attributes' for macOS, which currently only work when
 running Emacs as root.
 
 See this article by Bozhidar Batsov for an overview of Proced:
@@ -724,11 +724,11 @@ even though Emacs allows a user to customize such features.
 
 *** New features
 
-This section contains features unique to Nextstep and/or OS X.
+This section contains features unique to Nextstep and/or macOS.
 
 **** PressAndHold for writing accented character
 
-On OS X, many application support the press and hold pattern to
+On macOS, many application support the press and hold pattern to
 invoke a menu of accented characters.  (See example at
 https://support.apple.com/en-us/HT201586 .)
 
@@ -741,7 +741,7 @@ implemented in Emacs for a free system.
 
 **** Floating scroll bars
 
-In modern OS X applications, the scroll bar often floats over the
+In modern macOS applications, the scroll bar often floats over the
 content, and is invisible unless actually used.  This makes the user
 interface less cluttered and more area could be used to contain text.
 
@@ -804,7 +804,7 @@ This section contains issues where there is an ongoing debate.
 **** Key bindings of CMD and ALT
 
 Currently in the "ns" port, ALT is bound to Meta and CMD is bound to
-Super -- allowing the user to use typical OS X commands like CMD-A to
+Super -- allowing the user to use typical macOS commands like CMD-A to
 mark everything.
 
 Unfortunately, when using an international keyboard, you can't type
@@ -852,9 +852,10 @@ Emacs can be build in a number of different ways.  For each feature,
 consider if is really is "NS" specific, or if it should be applied to
 all build versions.
 
-- With the "NS" interface.  This is the normal way to build Emacs on OS X.
+- With the "NS" interface.  This is the normal way to build Emacs on
+  macOS.
 
-- With the "X11" interface.  On OS X, this is mainly of interest to
+- With the "X11" interface.  On macOS, this is mainly of interest to
   developers of Emacs to get a "reference" interface implementations.
   However, it might be of interest for people working remotely, as X11
   applications can be used over a network connection.
@@ -863,12 +864,12 @@ all build versions.
 
 *** Bugs
 
-**** Incorrect translation of Super modifier with Ctrl or Meta on OS X
+**** Incorrect translation of Super modifier with Ctrl or Meta on macOS
 
 When pressing 'M-s-a', Emacs replies "M-s-å is undefined".  What
 happened is a mix of Emacs view that Meta and Super has been pressed,
-and OS X view that ALT-a should yield "å" (U+00E5 LATIN SMALL LETTER A
-WITH RING ABOVE).
+and macOS view that ALT-a should yield "å" (U+00E5 LATIN SMALL LETTER
+A WITH RING ABOVE).
 
 The bug reports suggest two different patches; unfortunately, neither
 works properly.  For example:
diff --git a/etc/refcards/calccard.tex b/etc/refcards/calccard.tex
index 5ca8207e2c8..e692ca4b7d9 100644
--- a/etc/refcards/calccard.tex
+++ b/etc/refcards/calccard.tex
@@ -22,14 +22,18 @@
 
 % Copyright (C) 1987, 1992, 2001-2016 Free Software Foundation, Inc.
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -75,14 +79,10 @@
 \centerline{designed by Dave Gillespie and Stephen Gildea,}
 \centerline{for GNU Emacs Calc.}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
-%For copies of the GNU Emacs Calc manual, write to the Free Software
-%Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
-%MA 02110-1301, USA.
-%
 \endgroup}
 
 % make \bye not \outer so that the \def\bye in the \else clause below
diff --git a/etc/refcards/cs-dired-ref.tex b/etc/refcards/cs-dired-ref.tex
index d980170724d..c36167d5619 100644
--- a/etc/refcards/cs-dired-ref.tex
+++ b/etc/refcards/cs-dired-ref.tex
@@ -5,14 +5,18 @@
 % Author: Evgeny Roubinchtein <eroubinc@u.washington.edu>
 % Czech translation: Pavel Janík <Pavel@Janik.cz>, March 2001
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -57,9 +61,9 @@
 \centerline{using refcard layout designed by Stephen Gildea.}
 \centerline{Translated by Pavel Janík.}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/cs-refcard.tex b/etc/refcards/cs-refcard.tex
index ecd7064f977..154831029ab 100644
--- a/etc/refcards/cs-refcard.tex
+++ b/etc/refcards/cs-refcard.tex
@@ -8,14 +8,18 @@
 % 	Milan Zamazal <pdm@zamazal.org>, August 1999
 %	Pavel Janík <Pavel@Janik.cz>, November 2000 (Emacs 21)
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -74,9 +78,9 @@
 \centerline{Designed by Stephen Gildea}
 \centerline{Translated by Jan Buchal, Milan Zamazal, Pavel Janík}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/cs-survival.tex b/etc/refcards/cs-survival.tex
index bb38a916bb0..77893aec3ac 100644
--- a/etc/refcards/cs-survival.tex
+++ b/etc/refcards/cs-survival.tex
@@ -5,14 +5,18 @@
 % Author: Wlodek Bzyl <matwb@univ.gda.pl>
 % Czech translation: Pavel Janík <Pavel@Janik.cz>, March 2001
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -63,9 +67,11 @@
     W{\l}odek Bzyl (matwb@univ.gda.pl)\break
     Do češtiny přeložil Pavel Janík (Pavel@Janik.cz)
 
-    Kopie tohoto dokumentu můžete vytvářet a šířit
-    za předpokladu, že budou obsahovat tuto poznámku
-    o autorských právech.\par}}
+    Released under the terms of the GNU General Public License
+    version 3 or later.
+
+    \TeX{} source for this card is distributed with Emacs in
+    {\tt etc/refcards/}\par}}
 
 \hsize 3.2in
 \vsize 7.95in
diff --git a/etc/refcards/de-refcard.tex b/etc/refcards/de-refcard.tex
index 748f9f8add2..89636a84509 100644
--- a/etc/refcards/de-refcard.tex
+++ b/etc/refcards/de-refcard.tex
@@ -6,14 +6,18 @@
 % Author: Stephen Gildea <gildea@stop.mail-abuse.org>
 % German translation: Sven Joachim <svenjoac@gmx.de>
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -75,10 +79,10 @@
 \centerline{Entworfen von Stephen Gildea}
 % \centerline{deutsche \"Ubersetzung von Sven Joachim}
 
-Es ist gestattet, ver\"anderte und unver\"anderte Kopien dieser
-Karte her\-zu\-stellen und zu verbreiten, vorausgesetzt dass sich
-der Copyright-Hinweis und der Hinweis auf diese Erlaubnis auf allen
-Kopien befinden.
+Released under the terms of the GNU General Public License
+version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 F\"ur Kopien des Handbuchs zu GNU Emacs:
 
diff --git a/etc/refcards/dired-ref.tex b/etc/refcards/dired-ref.tex
index cef3f46fd81..5f8d8babcc3 100644
--- a/etc/refcards/dired-ref.tex
+++ b/etc/refcards/dired-ref.tex
@@ -4,14 +4,18 @@
 
 % Author: Evgeny Roubinchtein <eroubinc@u.washington.edu>
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -58,9 +62,9 @@
 \centerline{Originally written May 2000 by Evgeny Roubinchtein,}
 \centerline{using refcard layout designed by Stephen Gildea.}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/fr-dired-ref.tex b/etc/refcards/fr-dired-ref.tex
index c430a97ee0c..913372bc8cd 100644
--- a/etc/refcards/fr-dired-ref.tex
+++ b/etc/refcards/fr-dired-ref.tex
@@ -5,14 +5,18 @@
 % Author: Evgeny Roubinchtein <eroubinc@u.washington.edu>
 % French translation: Eric Jacoboni
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -51,9 +55,10 @@
 \centerline{Mis \`a jour pour Dired en Mai 2000 par Evgeny Roubinchtein}
 \centerline{Traduction fran\c{c}aise d'\'Eric Jacoboni}
 
-Vous pouvez faire et distribuer des copies de cette carte, pourvu que
-la notice de copyright et cette note de permission soient pr\'eserv\'ees
-sur toutes les copies.
+Released under the terms of the GNU General Public License
+version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 Pour obtenir des copies du manuel de GNU Emacs:
 
diff --git a/etc/refcards/fr-refcard.tex b/etc/refcards/fr-refcard.tex
index e63d34fdb4c..ddaa85befbe 100644
--- a/etc/refcards/fr-refcard.tex
+++ b/etc/refcards/fr-refcard.tex
@@ -7,14 +7,18 @@
 % French translation: Eric Jacoboni
 %	Micha\"el Cadilhac
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -72,9 +76,9 @@
 \centerline{Traduction fran\c{c}aise de Micha\"el Cadilhac}
 % previously: Eric Jacoboni
 
-Vous pouvez faire et distribuer des copies de cette carte, modifi\'ee ou
-non, pourvu que la note de copyright et cette note de permission
-soient conserv\'ees sur toutes les copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 Pour des copies du manuel GNU Emacs:
 
diff --git a/etc/refcards/fr-survival.tex b/etc/refcards/fr-survival.tex
index 1256de33f08..a6279e80d40 100644
--- a/etc/refcards/fr-survival.tex
+++ b/etc/refcards/fr-survival.tex
@@ -6,14 +6,18 @@
 % Author: Wlodek Bzyl <matwb@univ.gda.pl>
 % French translation:  \'Eric Jacoboni <jaco@teaser.fr>, November 2001
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -58,9 +62,11 @@
     Auteur W{\l}odek Bzyl (matwb@univ.gda.pl)\break
     Traduction fran\c{c}aise \'Eric Jacoboni (jaco@teaser.fr)
 
-    Vous pouvez faire et distribuer des copies de cette carte, pourvu
-    que la note de copyright, ainsi que cette notice soient
-    pr\'eserv\'ees sur toutes les copies.\par}}
+    Released under the terms of the GNU General Public License
+    version 3 or later.
+
+    \TeX{} source for this card is distributed with Emacs in {\tt
+      etc/refcards/}\par}}
 
 \hsize 3.2in
 \vsize 7.95in
diff --git a/etc/refcards/gnus-refcard.tex b/etc/refcards/gnus-refcard.tex
index d51e2aca639..46d0d7df225 100644
--- a/etc/refcards/gnus-refcard.tex
+++ b/etc/refcards/gnus-refcard.tex
@@ -123,9 +123,11 @@
     Copyright \copyright\ 1995, 2000, 2002--2016 Free Software Foundation, Inc.\\*
   \end{center}
 
-  Permission is granted to make and distribute copies of this reference
-  \guide{} provided the copyright notice and this permission are preserved on
-  all copies.  Please send corrections, additions and suggestions to the
+  Released under the terms of the GNU General Public License version 3 or later.
+
+  \TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
+
+  Please send corrections, additions and suggestions to the
   current maintainer's email address. \Guide{} last edited on \date.
   }
 
diff --git a/etc/refcards/orgcard.tex b/etc/refcards/orgcard.tex
index 20df7534d27..a5a66264557 100644
--- a/etc/refcards/orgcard.tex
+++ b/etc/refcards/orgcard.tex
@@ -20,14 +20,18 @@
 % Copyright (C) 1987, 1993, 1996-1997, 2001-2016 Free Software
 % Foundation, Inc.
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -73,9 +77,10 @@
 \centerline{Author: Philip Rooke}
 \centerline{based on refcard design and format by Stephen Gildea}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+\centerline{Released under the terms of the GNU General Public License}
+\centerline{version 3 or later.}
+
+\centerline{\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}}
 
 \endgroup}
 
diff --git a/etc/refcards/pl-refcard.tex b/etc/refcards/pl-refcard.tex
index e4fbb6f6e24..df370d4b504 100644
--- a/etc/refcards/pl-refcard.tex
+++ b/etc/refcards/pl-refcard.tex
@@ -6,14 +6,18 @@
 % Author: Stephen Gildea <gildea@stop.mail-abuse.org>
 % Polish translation: W{\l}odek Bzyl <matwb@univ.gda.pl>
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -84,9 +88,9 @@
 \centerline{projekt Stephen Gildea}
 \centerline{t/lumaczenie W/lodek Bzyl}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/pt-br-refcard.tex b/etc/refcards/pt-br-refcard.tex
index c1b31f85ac9..27849a3d8d3 100644
--- a/etc/refcards/pt-br-refcard.tex
+++ b/etc/refcards/pt-br-refcard.tex
@@ -6,14 +6,18 @@
 % Author: Stephen Gildea <gildea@stop.mail-abuse.org>
 % Portuguese translation: Rodrigo Real <rreal@ucpel.tche.br>
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -77,9 +81,9 @@
 \centerline{Designed by Stephen Gildea}
 \centerline{Translated by Rodrigo Real}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/refcard.tex b/etc/refcards/refcard.tex
index a5c74191dac..6eefd1560ce 100644
--- a/etc/refcards/refcard.tex
+++ b/etc/refcards/refcard.tex
@@ -5,14 +5,18 @@
 
 % Author: Stephen Gildea <gildea@stop.mail-abuse.org>
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -75,9 +79,9 @@
 \centerline{For GNU Emacs version \versionemacs}
 \centerline{Designed by Stephen Gildea}
 
-Permission is granted to make and distribute modified or unmodified
-copies of this card provided the copyright notice and this permission
-notice are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/ru-refcard.tex b/etc/refcards/ru-refcard.tex
index 03af6576bfe..1d96473fa6c 100644
--- a/etc/refcards/ru-refcard.tex
+++ b/etc/refcards/ru-refcard.tex
@@ -3,6 +3,25 @@
 % Author: Stephen Gildea <gildea@stop.mail-abuse.org>
 % Russian translation: Alex Ott <alexott@gmail.com>
 
+% This document is free software: you can redistribute it and/or modify
+% it under the terms of the GNU General Public License as published by
+% the Free Software Foundation, either version 3 of the License, or
+% (at your option) any later version.
+
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+% GNU General Public License for more details.
+
+% You should have received a copy of the GNU General Public License
+% along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
 \documentclass[10pt]{article}
 \usepackage{multicol,tabularx}
 \usepackage[a4paper,hmargin={2cm,2cm},vmargin={2cm,2cm},nohead,twoside]{geometry}
@@ -35,9 +54,9 @@
 \centerline{Designed by Stephen Gildea}
 \centerline{Перевод Alex Ott <alexott@gmail.com>}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/sk-dired-ref.tex b/etc/refcards/sk-dired-ref.tex
index 7bd5ceb5e13..81f112270f0 100644
--- a/etc/refcards/sk-dired-ref.tex
+++ b/etc/refcards/sk-dired-ref.tex
@@ -6,14 +6,18 @@
 % Czech translation: Pavel Janík <Pavel@Janik.cz>, March 2001
 % Slovak translation: Miroslav Vasko <vasko@debian.cz>, March 2001
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -58,9 +62,9 @@
 \centerline{using refcard layout designed by Stephen Gildea.}
 \centerline{Translated by Miroslav Vaško.}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/sk-refcard.tex b/etc/refcards/sk-refcard.tex
index 86f1919247c..27b3a38cd9c 100644
--- a/etc/refcards/sk-refcard.tex
+++ b/etc/refcards/sk-refcard.tex
@@ -9,14 +9,18 @@
 %	Pavel Janík <Pavel@Janik.cz>, November 2000 (Emacs 21)
 % Slovak translation: Miroslav Vaško <vasko@debian.cz>, March 2001
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -75,9 +79,9 @@
 \centerline{Designed by Stephen Gildea}
 \centerline{Translated by Miroslav Vaško}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/sk-survival.tex b/etc/refcards/sk-survival.tex
index f8db101c126..152009bd86f 100644
--- a/etc/refcards/sk-survival.tex
+++ b/etc/refcards/sk-survival.tex
@@ -6,14 +6,18 @@
 % Czech translation: Pavel Janík <Pavel@Janik.cz>, March 2001
 % Slovak translation: Miroslav Vasko <vasko@debian.cz>, March 2001
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -65,9 +69,11 @@
     Do češtiny preložil Pavel Janík (Pavel@Janik.cz)\break
     Do slovenčiny preložil Miroslav Vaško (vasko@debian.cz)
 
-    Kópie tohto dokumentu môžete vytvárať a šíriť
-    za predpokladu, že budú obsahovať túto poznámku
-    o autorských právach.\par}}
+    Released under the terms of the GNU General Public License
+    version 3 or later.
+
+    \TeX{} source for this card is distributed with Emacs in
+    {\tt etc/refcards/}\par}}
 
 \hsize 3.2in
 \vsize 7.95in
diff --git a/etc/refcards/survival.tex b/etc/refcards/survival.tex
index 02d310f5897..2d81b309906 100644
--- a/etc/refcards/survival.tex
+++ b/etc/refcards/survival.tex
@@ -5,14 +5,18 @@
 
 % Author: Wlodek Bzyl <matwb@univ.gda.pl>
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -52,9 +56,11 @@
     For GNU Emacs version \versionemacs\break
     Author W{\l}odek Bzyl (matwb@univ.gda.pl)
 
-    Permission is granted to make and distribute copies of
-    this card provided the copyright notice and this permission notice
-    are preserved on all copies.\par}}
+    Released under the terms of the GNU General Public License
+    version 3 or later.
+
+    \TeX{} source for this card is distributed with Emacs in
+    {\tt etc/refcards/}\par}}
 
 \hsize 3.2in
 \vsize 7.95in
diff --git a/etc/refcards/vipcard.tex b/etc/refcards/vipcard.tex
index 942ec6cf300..5eca55cc582 100644
--- a/etc/refcards/vipcard.tex
+++ b/etc/refcards/vipcard.tex
@@ -4,14 +4,18 @@
 
 % Author: Masahiko Sato <ms@sail.stanford.edu>, <masahiko@sato.riec.tohoku.junet>
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -67,9 +71,9 @@
 \centerline{Written by Masahiko Sato,}
 \centerline{using refcard layout designed by Stephen Gildea.}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/etc/refcards/viperCard.tex b/etc/refcards/viperCard.tex
index 35528b193c7..d984ffc484f 100644
--- a/etc/refcards/viperCard.tex
+++ b/etc/refcards/viperCard.tex
@@ -6,14 +6,18 @@
 %	Aamod Sane <sane@cs.uiuc.edu> (VIP 4.3)
 %	Masahiko Sato <ms@sail.stanford.edu> (VIP 3.5)
 
-% This file is part of GNU Emacs.
-
-% GNU Emacs is free software: you can redistribute it and/or modify
+% This document is free software: you can redistribute it and/or modify
 % it under the terms of the GNU General Public License as published by
 % the Free Software Foundation, either version 3 of the License, or
 % (at your option) any later version.
 
-% GNU Emacs is distributed in the hope that it will be useful,
+% As a special additional permission, you may distribute reference cards
+% printed, or formatted for printing, with the notice "Released under
+% the terms of the GNU General Public License version 3 or later"
+% instead of the usual distributed-under-the-GNU-GPL notice, and without
+% a copy of the GPL itself.
+
+% This document is distributed in the hope that it will be useful,
 % but WITHOUT ANY WARRANTY; without even the implied warranty of
 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 % GNU General Public License for more details.
@@ -71,9 +75,9 @@
 \centerline{by Aamod Sane, VIP version 4.3}
 \centerline{by Masahiko Sato, VIP version 3.5}
 
-Permission is granted to make and distribute copies of
-this card provided the copyright notice and this permission notice
-are preserved on all copies.
+Released under the terms of the GNU General Public License version 3 or later.
+
+\TeX{} source for this card is distributed with Emacs in {\tt etc/refcards/}
 
 For copies of the GNU Emacs manual, see:
 
diff --git a/lib-src/Makefile.in b/lib-src/Makefile.in
index 150d943b7e2..c3693abf341 100644
--- a/lib-src/Makefile.in
+++ b/lib-src/Makefile.in
@@ -75,7 +75,7 @@ am__v_at_1 =
 
 # ==================== Where To Install Things ====================
 
-# Location to install Emacs.app under GNUstep / Mac OS X.
+# Location to install Emacs.app under GNUstep / macOS.
 # Later values may use this.
 ns_appbindir=@ns_appbindir@
 
diff --git a/lisp/arc-mode.el b/lisp/arc-mode.el
index b5373c607d4..c42ca813e96 100644
--- a/lisp/arc-mode.el
+++ b/lisp/arc-mode.el
@@ -1646,7 +1646,7 @@ This doesn't recover lost files, it just undoes changes in the buffer itself."
         ;;   converts "\" to "/".
         ;; - For 0 generic: generic_to_unix_filename() downcases if there's
         ;;   no lower case already present, and converts "\" to "/".
-        ;; - For 'm' MacOS: macos_to_unix_filename() changes "/" to ":" and
+        ;; - For 'm' macOS: macos_to_unix_filename() changes "/" to ":" and
         ;;   ":" to "/"
 	(setq fiddle (cond ((= ?M osid) t)
                            ((= 0 osid)  (string= efnname (upcase efnname)))))
diff --git a/lisp/auth-source.el b/lisp/auth-source.el
index 96693644ceb..62d9a4521c0 100644
--- a/lisp/auth-source.el
+++ b/lisp/auth-source.el
@@ -417,13 +417,13 @@ with \"[a/b/c] \" if CHOICES is \(?a ?b ?c)."
     ;; Keychain collection matching any user, host, and protocol
     ((eq entry 'macos-keychain-generic)
      (auth-source-backend-parse '(:source (:macos-keychain-generic default))))
-    ;; take macos-keychain-internet:XYZ and recurse to get it as MacOS
+    ;; take macos-keychain-internet:XYZ and recurse to get it as macOS
     ;; Keychain "XYZ" matching any user, host, and protocol
     ((and (stringp entry) (string-match "^macos-keychain-internet:\\(.+\\)"
                                         entry))
      (auth-source-backend-parse `(:source (:macos-keychain-internet
                                            ,(match-string 1 entry)))))
-    ;; take macos-keychain-generic:XYZ and recurse to get it as MacOS
+    ;; take macos-keychain-generic:XYZ and recurse to get it as macOS
     ;; Keychain "XYZ" matching any user, host, and protocol
     ((and (stringp entry) (string-match "^macos-keychain-generic:\\(.+\\)"
                                         entry))
@@ -452,7 +452,7 @@ with \"[a/b/c] \" if CHOICES is \(?a ?b ?c)."
         :search-function #'auth-source-netrc-search
         :create-function #'auth-source-netrc-create)))
 
-    ;; the MacOS Keychain
+    ;; the macOS Keychain
     ((and
       (not (null (plist-get entry :source))) ; the source must not be nil
       (listp (plist-get entry :source))      ; and it must be a list
@@ -1647,7 +1647,7 @@ authentication tokens:
 (cl-defun auth-source-macos-keychain-search (&rest spec
                                              &key backend create delete type max
                                              &allow-other-keys)
-  "Search the MacOS Keychain; spec is like `auth-source'.
+  "Search the macOS Keychain; spec is like `auth-source'.
 
 All search keys must match exactly.  If you need substring
 matching, do a wider search and narrow it down yourself.
@@ -1669,13 +1669,13 @@ Similarly, :host maps to \"-c HOST\" (the \"creator\" keychain
 field), :user maps to \"-a USER\", and :port maps to \"-s PORT\".
 
 Here's an example that looks for the first item in the default
-generic MacOS Keychain:
+generic macOS Keychain:
 
  (let ((auth-sources \\='(macos-keychain-generic)))
     (auth-source-search :max 1)
 
 Here's another that looks for the first item in the internet
-MacOS Keychain collection whose label is `gnus':
+macOS Keychain collection whose label is `gnus':
 
  (let ((auth-sources \\='(macos-keychain-internet)))
     (auth-source-search :max 1 :label \"gnus\")
@@ -1688,11 +1688,11 @@ entries for git.gnus.org:
 "
   ;; TODO
   (cl-assert (not create) nil
-          "The MacOS Keychain auth-source backend doesn't support creation yet")
+          "The macOS Keychain auth-source backend doesn't support creation yet")
   ;; TODO
   ;; (macos-keychain-delete-item coll elt)
   (cl-assert (not delete) nil
-          "The MacOS Keychain auth-source backend doesn't support deletion yet")
+          "The macOS Keychain auth-source backend doesn't support deletion yet")
 
   (let* ((coll (oref backend source))
          (max (or max 5000))     ; sanity check: default to stop at 5K
diff --git a/lisp/battery.el b/lisp/battery.el
index 10a34034019..24eb8a58f63 100644
--- a/lisp/battery.el
+++ b/lisp/battery.el
@@ -22,10 +22,10 @@
 
 ;;; Commentary:
 
-;; There is at present support for GNU/Linux, OS X and Windows.  This
+;; There is at present support for GNU/Linux, macOS and Windows.  This
 ;; library supports both the `/proc/apm' file format of Linux version
 ;; 1.3.58 or newer and the `/proc/acpi/' directory structure of Linux
-;; 2.4.20 and 2.6.  Darwin (OS X) is supported by using the `pmset'
+;; 2.4.20 and 2.6.  Darwin (macOS) is supported by using the `pmset'
 ;; program.  Windows is supported by the GetSystemPowerStatus API call.
 
 ;;; Code:
@@ -604,7 +604,7 @@ The following %-sequences are provided:
 	  (cons ?t (or remaining-time "N/A")))))
 
 
-;;; `pmset' interface for Darwin (OS X).
+;;; `pmset' interface for Darwin (macOS).
 
 (defun battery-pmset ()
   "Get battery status information using `pmset'.
diff --git a/lisp/cedet/semantic/bovine/gcc.el b/lisp/cedet/semantic/bovine/gcc.el
index ec292395f12..b56b268ca0d 100644
--- a/lisp/cedet/semantic/bovine/gcc.el
+++ b/lisp/cedet/semantic/bovine/gcc.el
@@ -225,7 +225,7 @@ It should also include other symbols GCC was compiled with.")
         (setq semantic-lex-c-preprocessor-symbol-map nil))
     (dolist (D defines)
       (add-to-list 'semantic-lex-c-preprocessor-symbol-map D))
-    ;; Needed for parsing OS X libc
+    ;; Needed for parsing macOS libc
     (when (eq system-type 'darwin)
       (add-to-list 'semantic-lex-c-preprocessor-symbol-map '("__i386__" . "")))
     (when (featurep 'semantic/bovine/c)
diff --git a/lisp/chistory.el b/lisp/chistory.el
index 6f8a74b2a67..be5393720ac 100644
--- a/lisp/chistory.el
+++ b/lisp/chistory.el
@@ -95,7 +95,7 @@ from the command history."
 
 ;;;###autoload
 (defun list-command-history ()
-  "List history of commands typed to minibuffer.
+  "List history of commands that used the minibuffer.
 The number of commands listed is controlled by `list-command-history-max'.
 Calls value of `list-command-history-filter' (if non-nil) on each history
 element to judge if that element should be excluded from the list.
diff --git a/lisp/dabbrev.el b/lisp/dabbrev.el
index d9f36b15290..438eda3776d 100644
--- a/lisp/dabbrev.el
+++ b/lisp/dabbrev.el
@@ -433,7 +433,10 @@ Expands to the most recent, preceding word for which this is a prefix.
 If no suitable preceding word is found, words following point are
 considered.  If still no suitable word is found, then look in the
 buffers accepted by the function pointed out by variable
-`dabbrev-friend-buffer-function'.
+`dabbrev-friend-buffer-function', if `dabbrev-check-other-buffers'
+says so.  Then, if `dabbrev-check-all-buffers' is non-nil, look in
+all the other buffers, subject to constraints specified
+by `dabbrev-ignored-buffer-names' and `dabbrev-ignored-regexps'.
 
 A positive prefix argument, N, says to take the Nth backward *distinct*
 possibility.  A negative argument says search forward.
diff --git a/lisp/emacs-lisp/cl-preloaded.el b/lisp/emacs-lisp/cl-preloaded.el
index cd1d700f1b0..2b022c49053 100644
--- a/lisp/emacs-lisp/cl-preloaded.el
+++ b/lisp/emacs-lisp/cl-preloaded.el
@@ -45,7 +45,7 @@
 
 (defun cl--assertion-failed (form &optional string sargs args)
   (if debug-on-error
-      (debug `(cl-assertion-failed ,form ,string ,@sargs))
+      (funcall debugger `(cl-assertion-failed ,form ,string ,@sargs))
     (if string
         (apply #'error string (append sargs args))
       (signal 'cl-assertion-failed `(,form ,@sargs)))))
diff --git a/lisp/faces.el b/lisp/faces.el
index 6e3b08cb02b..f536015e981 100644
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -108,7 +108,7 @@ a font height that isn't optimal."
      "Courier 10 Pitch"
      ;; This looks good on MS-Windows and OS X.
      "Consolas"
-     ;; This looks good on OS X.  "Courier" looks good too, but is
+     ;; This looks good on macOS.  "Courier" looks good too, but is
      ;; jagged on GNU/Linux and so is listed later as "courier".
      "Courier Std"
      ;; Although these are anti-aliased, they are a bit faint compared
diff --git a/lisp/international/fontset.el b/lisp/international/fontset.el
index 612c0a08ad7..659f03a2a67 100644
--- a/lisp/international/fontset.el
+++ b/lisp/international/fontset.el
@@ -812,10 +812,11 @@
              (#x1F700 . #x1F77F)	;; Alchemical Symbols
              (#x1F780 . #x1F7FF)	;; Geometric Shapes Extended
              (#x1F800 . #x1F8FF)))	;; Supplemental Arrows-C
-    (set-fontset-font "fontset-default" symbol-subgroup "Symbola" nil 'prepend))
+    (set-fontset-font "fontset-default" symbol-subgroup
+                      '("Symbola" . "iso10646-1") nil 'prepend))
   ;; Box Drawing and Block Elements
   (set-fontset-font "fontset-default" '(#x2500 . #x259F)
-                    "FreeMono" nil 'prepend)
+                    '("FreeMono" . "iso10646-1") nil 'prepend)
 
   ;; Since standard-fontset-spec on X uses fixed-medium font, which
   ;; gets mapped to a iso8859-1 variant, we would like to prefer its
diff --git a/lisp/international/mule-cmds.el b/lisp/international/mule-cmds.el
index 28eec4f0df9..7543d0d734a 100644
--- a/lisp/international/mule-cmds.el
+++ b/lisp/international/mule-cmds.el
@@ -2723,7 +2723,7 @@ See also `locale-charset-language-names', `locale-language-names',
       ;; On Darwin, file names are always encoded in utf-8, no matter
       ;; the locale.
       (setq default-file-name-coding-system 'utf-8)
-      ;; Mac OS X's Terminal.app by default uses utf-8 regardless of
+      ;; macOS's Terminal.app by default uses utf-8 regardless of
       ;; the locale.
       (when (and (null window-system)
 		 (equal (getenv "TERM_PROGRAM" frame) "Apple_Terminal"))
diff --git a/lisp/international/ucs-normalize.el b/lisp/international/ucs-normalize.el
index cf2e81e20f2..b2bc622858d 100644
--- a/lisp/international/ucs-normalize.el
+++ b/lisp/international/ucs-normalize.el
@@ -621,7 +621,7 @@ COMPOSITION-PREDICATE will be used to compose region."
 
 ;;; coding-system definition
 (define-coding-system 'utf-8-hfs
-  "UTF-8 based coding system for MacOS HFS file names.
+  "UTF-8 based coding system for macOS HFS file names.
 The singleton characters in HFS normalization exclusion will not
 be decomposed."
   :coding-type 'utf-8
diff --git a/lisp/ls-lisp.el b/lisp/ls-lisp.el
index 11cbea0b373..8395622546d 100644
--- a/lisp/ls-lisp.el
+++ b/lisp/ls-lisp.el
@@ -75,7 +75,7 @@
 	((memq system-type '(hpux usg-unix-v berkeley-unix))
 	 'UNIX))	; very similar to GNU
   ;; Anything else defaults to nil, meaning GNU.
-  "Platform to emulate: GNU (default), MacOS, MS-Windows, UNIX.
+  "Platform to emulate: GNU (default), macOS, MS-Windows, UNIX.
 Corresponding value is one of: nil, `MacOS', `MS-Windows', `UNIX'.
 Set this to your preferred value; it need not match the actual platform
 you are using.
diff --git a/lisp/mail/emacsbug.el b/lisp/mail/emacsbug.el
index 18eaa22b34c..650fbfa13d2 100644
--- a/lisp/mail/emacsbug.el
+++ b/lisp/mail/emacsbug.el
@@ -72,7 +72,7 @@
 (defvar message-strip-special-text-properties)
 
 (defun report-emacs-bug-can-use-osx-open ()
-  "Return non-nil if the OS X \"open\" command is available for mailing."
+  "Return non-nil if the macOS \"open\" command is available for mailing."
   (and (featurep 'ns)
        (equal (executable-find "open") "/usr/bin/open")
        (memq system-type '(darwin))))
@@ -107,7 +107,7 @@ This requires you to be running either Gnome, KDE, or Xfce4."
 
 (defun report-emacs-bug-insert-to-mailer ()
   "Send the message to your preferred mail client.
-This requires either the OS X \"open\" command, or the freedesktop
+This requires either the macOS \"open\" command, or the freedesktop
 \"xdg-email\" command to be available."
   (interactive)
   (save-excursion
diff --git a/lisp/man.el b/lisp/man.el
index 82691f5e9b7..a140e03d74a 100644
--- a/lisp/man.el
+++ b/lisp/man.el
@@ -881,7 +881,7 @@ test/automated/man-tests.el in the emacs repository."
           (setq default-directory "/") ;; in case inherited doesn't exist
           ;; Actually for my `man' the arg is a regexp.
           ;; POSIX says it must be ERE and "man-db" seems to agree,
-          ;; whereas under MacOSX it seems to be BRE-style and doesn't
+          ;; whereas under macOS it seems to be BRE-style and doesn't
           ;; accept backslashes at all.  Let's not bother to
           ;; quote anything.
           (let ((process-environment (copy-sequence process-environment)))
diff --git a/lisp/menu-bar.el b/lisp/menu-bar.el
index 9f3156d62b2..d21fa2cd61c 100644
--- a/lisp/menu-bar.el
+++ b/lisp/menu-bar.el
@@ -1865,7 +1865,7 @@ key, a click, or a menu-item"))
       '(menu-item "Emacs Tutorial" help-with-tutorial
                   :help "Learn how to use Emacs"))
 
-    ;; In OS X it's in the app menu already.
+    ;; In macOS it's in the app menu already.
     ;; FIXME? There already is an "About Emacs" (sans ...) entry in the Help menu.
     (and (featurep 'ns)
          (not (eq system-type 'darwin))
diff --git a/lisp/net/ange-ftp.el b/lisp/net/ange-ftp.el
index 9ff9997e728..07c3daf7d7e 100644
--- a/lisp/net/ange-ftp.el
+++ b/lisp/net/ange-ftp.el
@@ -740,7 +740,7 @@ These mean that the FTP process should be (or already has been) killed."
   :type 'regexp)
 
 (defcustom ange-ftp-potential-error-msgs
-  ;; On Mac OS X we sometimes get things like:
+  ;; On macOS we sometimes get things like:
   ;;
   ;;     ftp> open ftp.nluug.nl
   ;;     Trying 2001:610:1:80aa:192:87:102:36...
diff --git a/lisp/net/browse-url.el b/lisp/net/browse-url.el
index 15f6df742cc..b2077d784c0 100644
--- a/lisp/net/browse-url.el
+++ b/lisp/net/browse-url.el
@@ -44,7 +44,7 @@
 ;; browse-url-text-*	              Any text browser     0
 ;; browse-url-generic                 arbitrary
 ;; browse-url-default-windows-browser MS-Windows browser
-;; browse-url-default-macosx-browser  Mac OS X browser
+;; browse-url-default-macosx-browser  macOS browser
 ;; browse-url-xdg-open                Free Desktop xdg-open on Gnome, KDE, Xfce4, LXDE
 ;; browse-url-kde                     KDE konqueror (kfm)
 ;; browse-url-elinks                  Elinks      Don't know (tried with 0.12.GIT)
@@ -162,7 +162,7 @@ regexp should probably be \".\" to specify a default browser."
 			 :value browse-url-generic)
 	  (function-item :tag "Default Windows browser"
 			 :value browse-url-default-windows-browser)
-	  (function-item :tag "Default Mac OS X browser"
+	  (function-item :tag "Default macOS browser"
 			 :value browse-url-default-macosx-browser)
 	  (function-item :tag "Default browser"
 			 :value browse-url-default-browser)
@@ -881,7 +881,7 @@ The optional NEW-WINDOW argument is not used."
 	(t (w32-shell-execute "open" url))))
 
 (defun browse-url-default-macosx-browser (url &optional _new-window)
-  "Invoke the MacOS X system's default Web browser.
+  "Invoke the macOS system's default Web browser.
 The optional NEW-WINDOW argument is not used"
   (interactive (browse-url-interactive-arg "URL: "))
   (start-process (concat "open " url) nil "open" url))
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 9496ebf7563..f44a4d37e78 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -1293,7 +1293,7 @@ target of the symlink differ."
 		 res-uid res-gid res-size res-symlink-target)
     (tramp-message vec 5 "file attributes with ls: %s" localname)
     ;; We cannot send all three commands combined, it could exceed
-    ;; NAME_MAX or PATH_MAX.  Happened on Mac OS X, for example.
+    ;; NAME_MAX or PATH_MAX.  Happened on macOS, for example.
     (when (or (tramp-send-command-and-check
                vec
                (format "%s %s"
@@ -4123,7 +4123,7 @@ process to set up.  VEC specifies the connection."
 	(goto-char (point-min))
 	(when (search-forward "\r" nil t)
 	  (setq cs-decode (coding-system-change-eol-conversion cs-decode 'dos)))
-	;; Special setting for Mac OS X.
+	;; Special setting for macOS.
 	(when (and (string-match "^Darwin" uname)
 		   (memq 'utf-8-hfs (coding-system-list)))
 	  (setq cs-decode 'utf-8-hfs
@@ -4178,7 +4178,7 @@ process to set up.  VEC specifies the connection."
 	(tramp-send-command vec "stty tabs" t)
       (tramp-send-command vec "stty tab0" t))
 
-    ;; Set utf8 encoding.  Needed for Mac OS X, for example.  This is
+    ;; Set utf8 encoding.  Needed for macOS, for example.  This is
     ;; non-POSIX, so we must expect errors on some systems.
     (tramp-send-command vec "stty iutf8 2>/dev/null" t)
 
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index e9697ff2e1e..60199d2047e 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -981,7 +981,7 @@ this variable to be set as well."
   :require 'tramp)
 
 ;; Logging in to a remote host normally requires obtaining a pty.  But
-;; Emacs on MacOS X has process-connection-type set to nil by default,
+;; Emacs on macOS has process-connection-type set to nil by default,
 ;; so on those systems Tramp doesn't obtain a pty.  Here, we allow
 ;; for an override of the system default.
 (defcustom tramp-process-connection-type t
diff --git a/lisp/org/org.el b/lisp/org/org.el
index 30ef5e83bdd..15f45822026 100644
--- a/lisp/org/org.el
+++ b/lisp/org/org.el
@@ -1940,7 +1940,7 @@ See `org-file-apps'.")
     ("eps.gz" . "gv %s")
     ("dvi"    . "xdvi %s")
     ("fig"    . "xfig %s"))
-  "Default file applications on a MacOS X system.
+  "Default file applications on a macOS system.
 The system \"open\" is known as a default, but we use X11 applications
 for some files for which the OS does not have a good default.
 See `org-file-apps'.")
@@ -2015,7 +2015,7 @@ file identifier are
                (\"html\" . default) to the list as well.
  t             Default for files not matched by any of the other options.
  `system'      The system command to open files, like `open' on Windows
-               and Mac OS X, and mailcap under GNU/Linux.  This is the command
+               and macOS, and mailcap under GNU/Linux.  This is the command
                that will be selected if you call `C-c C-o' with a double
                \\[universal-argument] \\[universal-argument] prefix.
 
diff --git a/lisp/outline.el b/lisp/outline.el
index 6345bb59df4..dca5f1a7de8 100644
--- a/lisp/outline.el
+++ b/lisp/outline.el
@@ -788,7 +788,8 @@ Show the heading too, if it is currently invisible."
     'show-entry 'outline-show-entry "25.1")
 
 (defun outline-hide-body ()
-  "Hide all body lines in buffer, leaving all headings visible."
+  "Hide all body lines in buffer, leaving all headings visible.
+Note that this does not hide the lines preceding the first heading line."
   (interactive)
   (outline-hide-region-body (point-min) (point-max)))
 
@@ -868,7 +869,12 @@ Show the heading too, if it is currently invisible."
 		       nil))
 
 (defun outline-hide-sublevels (levels)
-  "Hide everything but the top LEVELS levels of headers, in whole buffer."
+  "Hide everything but the top LEVELS levels of headers, in whole buffer.
+This also unhides the top heading-less body, if any.
+
+Interactively, the prefix argument supplies the value of LEVELS.
+When invoked without a prefix argument, LEVELS defaults to the level
+of the current heading, or to 1 if the current line is not a heading."
   (interactive (list
 		(cond
 		 (current-prefix-arg (prefix-numeric-value current-prefix-arg))
@@ -909,7 +915,8 @@ Show the heading too, if it is currently invisible."
     'hide-sublevels 'outline-hide-sublevels "25.1")
 
 (defun outline-hide-other ()
-  "Hide everything except current body and parent and top-level headings."
+  "Hide everything except current body and parent and top-level headings.
+This also unhides the top heading-less body, if any."
   (interactive)
   (outline-hide-sublevels 1)
   (let (outline-view-change-hook)
diff --git a/lisp/printing.el b/lisp/printing.el
index 7cdfb49a90f..7cf0afbf1fd 100644
--- a/lisp/printing.el
+++ b/lisp/printing.el
@@ -2272,7 +2272,7 @@ Useful links:
 * gv 3.5, June 1997
   `http://www.cs.wisc.edu/~ghost/gv/gv_doc/gv.html'
 
-* MacGSView (MacOS)
+* MacGSView (Mac OS)
   `http://www.cs.wisc.edu/~ghost/macos/index.htm'
 "
   :type '(string :tag "Ghostview Utility")
diff --git a/lisp/progmodes/gdb-mi.el b/lisp/progmodes/gdb-mi.el
index a2d4f143509..4f8709a21d7 100644
--- a/lisp/progmodes/gdb-mi.el
+++ b/lisp/progmodes/gdb-mi.el
@@ -69,12 +69,12 @@
 ;;   2) Use MinGW GDB instead.
 ;;   3) Use cygwin-mount.el
 
-;;; Mac OSX:
+;;; macOS:
 
-;; GDB in Emacs on Mac OSX works best with FSF GDB as Apple have made
-;; some changes to the version that they include as part of Mac OSX.
-;; This requires GDB version 7.0 or later (estimated release date Aug 2009)
-;; as earlier versions do not compile on Mac OSX.
+;; GDB in Emacs on macOS works best with FSF GDB as Apple have made
+;; some changes to the version that they include as part of macOS.
+;; This requires GDB version 7.0 or later as earlier versions do not
+;; compile on macOS.
 
 ;;; Known Bugs:
 
diff --git a/lisp/progmodes/idlwave.el b/lisp/progmodes/idlwave.el
index 9cb2ca74063..bc607ac4019 100644
--- a/lisp/progmodes/idlwave.el
+++ b/lisp/progmodes/idlwave.el
@@ -420,22 +420,22 @@ A value of t means to show all source files."
   :type 'integer)
 
 (defcustom idlwave-library-path nil
-  "Library path for Windows and MacOS (OS9).  Not needed under UNIX.
+  "Library path for Windows and Mac OS (OS9).  Not needed under UNIX.
 When selecting the directories to scan for IDL user catalog routine
 info, IDLWAVE can, under UNIX, query the shell for the exact search
-path \(the value of !PATH).  However, under Windows and MacOS
-\(pre-OSX), the IDLWAVE shell does not work.  In this case, this
-variable can be set to specify the paths where IDLWAVE can find PRO
-files.  The shell will only be asked for a list of paths when this
-variable is nil.  The value is a list of directories.  A directory
+path (the value of !PATH).  However, under MS-Windows, the
+IDLWAVE shell does not work.  In this case, this variable can be
+set to specify the paths where IDLWAVE can find PRO files.  The
+shell will only be asked for a list of paths when this variable
+is nil.  The value is a list of directories.  A directory
 preceded by a `+' will be searched recursively.  If you set this
-variable on a UNIX system, the shell will not be queried.  See also
-`idlwave-system-directory'."
+variable on a UNIX system, the shell will not be queried.  See
+also `idlwave-system-directory'."
   :group 'idlwave-routine-info
   :type '(repeat (directory)))
 
 (defcustom idlwave-system-directory ""
-  "The IDL system directory for Windows and MacOS.  Not needed under
+  "The IDL system directory for Windows and Mac OS.  Not needed under
 UNIX.  Set this to the value of the `!DIR' system variable in IDL.
 IDLWAVE uses this to find out which of the library routines belong to
 the official system library.  All files inside the `lib' subdirectory
diff --git a/lisp/progmodes/js.el b/lisp/progmodes/js.el
index 5d5d101835a..6fff981c6bd 100644
--- a/lisp/progmodes/js.el
+++ b/lisp/progmodes/js.el
@@ -1758,6 +1758,10 @@ This performs fontification according to `js--class-styles'."
                (and (js--re-search-backward "[?:{]\\|\\_<case\\_>" nil t)
                     (eq (char-after) ??))))
          (not (and
+               (eq (char-after) ?/)
+               (save-excursion
+                 (eq (nth 3 (syntax-ppss)) ?/))))
+         (not (and
                (eq (char-after) ?*)
                ;; Generator method (possibly using computed property).
                (looking-at (concat "\\* *\\(?:\\[\\|" js--name-re " *(\\)"))
diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 9cd9cc8b7c0..be96ac32a01 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -2436,7 +2436,7 @@ banner and the initial prompt are received separately."
 (defun python-shell-comint-end-of-output-p (output)
   "Return non-nil if OUTPUT is ends with input prompt."
   (string-match
-   ;; XXX: It seems on OSX an extra carriage return is attached
+   ;; XXX: It seems on macOS an extra carriage return is attached
    ;; at the end of output, this handles that too.
    (concat
     "\r?\n?"
@@ -5170,7 +5170,7 @@ returned as is."
   (add-to-list
    'hs-special-modes-alist
    `(python-mode
-     "\\s-*\\(?:def\\|class\\)\\>"
+     "\\s-*\\_<\\(?:def\\|class\\)\\_>"
      ;; Use the empty string as end regexp so it doesn't default to
      ;; "\\s)".  This way parens at end of defun are properly hidden.
      ""
diff --git a/lisp/simple.el b/lisp/simple.el
index 2506c4a59a8..91dee30b218 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -5517,13 +5517,13 @@ after C-u \\[set-mark-command]."
   :group 'editing-basics)
 
 (defun set-mark-command (arg)
-  "Set the mark where point is, or jump to the mark.
+  "Set the mark where point is, and activate it; or jump to the mark.
 Setting the mark also alters the region, which is the text
 between point and mark; this is the closest equivalent in
 Emacs to what some editors call the \"selection\".
 
 With no prefix argument, set the mark at point, and push the
-old mark position on local mark ring.  Also push the old mark on
+old mark position on local mark ring.  Also push the new mark on
 global mark ring, if the previous mark was set in another buffer.
 
 When Transient Mark Mode is off, immediately repeating this
diff --git a/lisp/term.el b/lisp/term.el
index c067254f414..a4c652bad7f 100644
--- a/lisp/term.el
+++ b/lisp/term.el
@@ -849,6 +849,7 @@ is buffer-local."
     (define-key map [S-insert] 'term-paste)
     (define-key map [prior] 'term-send-prior)
     (define-key map [next] 'term-send-next)
+    (define-key map [xterm-paste] #'term--xterm-paste)
     map)
   "Keyboard map for sending characters directly to the inferior process.")
 
@@ -1204,6 +1205,13 @@ without any interpretation."
   (interactive)
    (term-send-raw-string (current-kill 0)))
 
+(defun term--xterm-paste ()
+  "Insert the text pasted in an XTerm bracketed paste operation."
+  (interactive)
+  (term-send-raw-string (xterm--pasted-text)))
+
+(declare-function xterm--pasted-text "term/xterm" ())
+
 ;; Which would be better:  "\e[A" or "\eOA"? readline accepts either.
 ;; For my configuration it's definitely better \eOA but YMMV. -mm
 ;; For example: vi works with \eOA while elm wants \e[A ...
diff --git a/lisp/term/ns-win.el b/lisp/term/ns-win.el
index 5080ed0a8f7..41d6d72812b 100644
--- a/lisp/term/ns-win.el
+++ b/lisp/term/ns-win.el
@@ -1,4 +1,4 @@
-;;; ns-win.el --- lisp side of interface with NeXT/Open/GNUstep/MacOS X window system  -*- lexical-binding: t -*-
+;;; ns-win.el --- lisp side of interface with NeXT/Open/GNUstep/macOS window system  -*- lexical-binding: t -*-
 
 ;; Copyright (C) 1993-1994, 2005-2016 Free Software Foundation, Inc.
 
@@ -41,7 +41,7 @@
 ;;; Code:
 (eval-when-compile (require 'cl-lib))
 (or (featurep 'ns)
-    (error "%s: Loading ns-win.el but not compiled for GNUstep/MacOS"
+    (error "%s: Loading ns-win.el but not compiled for GNUstep/macOS"
            (invocation-name)))
 
 ;; Documentation-purposes only: actually loaded in loadup.el.
@@ -54,7 +54,7 @@
 (require 'ucs-normalize)
 
 (defgroup ns nil
-  "GNUstep/Mac OS X specific features."
+  "GNUstep/macOS specific features."
   :group 'environment)
 
 ;;;; Command line argument handling.
@@ -338,7 +338,7 @@ See `ns-insert-working-text'."
   (setq ns-working-overlay nil))
 
 
-;; OS X file system Unicode UTF-8 NFD (decomposed form) support.
+;; macOS file system Unicode UTF-8 NFD (decomposed form) support.
 (when (eq system-type 'darwin)
   ;; Used prior to Emacs 25.
   (define-coding-system-alias 'utf-8-nfd 'utf-8-hfs)
@@ -641,7 +641,7 @@ This function has been overloaded in Nextstep.")
   (set-frame-font ns-input-font))
 
 
-;; Default fontset for Mac OS X.  This is mainly here to show how a fontset
+;; Default fontset for macOS.  This is mainly here to show how a fontset
 ;; can be set up manually.  Ordinarily, fontsets are auto-created whenever
 ;; a font is chosen by
 (defvar ns-standard-fontset-spec
@@ -655,7 +655,7 @@ This function has been overloaded in Nextstep.")
              ",")
   "String of fontset spec of the standard fontset.
 This defines a fontset consisting of the Courier and other fonts that
-come with OS X.
+come with macOS.
 See the documentation of `create-fontset-from-fontset-spec' for the format.")
 
 (defvar ns-reg-to-script)               ; nsfont.m
@@ -844,7 +844,7 @@ See the documentation of `create-fontset-from-fontset-spec' for the format.")
                     (setq default-process-coding-system
                           '(utf-8-unix . utf-8-unix)))))
 
-  ;; OS X Lion introduces PressAndHold, which is unsupported by this port.
+  ;; Mac OS X Lion introduces PressAndHold, which is unsupported by this port.
   ;; See this thread for more details:
   ;; http://lists.gnu.org/archive/html/emacs-devel/2011-06/msg00505.html
   (ns-set-resource nil "ApplePressAndHoldEnabled" "NO")
diff --git a/lisp/term/xterm.el b/lisp/term/xterm.el
index 01c01130e7c..5fc6056ca23 100644
--- a/lisp/term/xterm.el
+++ b/lisp/term/xterm.el
@@ -784,7 +784,7 @@ We run the first FUNCTION whose STRING matches the input events."
       ;; Try to find out the type of terminal by sending a "Secondary
       ;; Device Attributes (DA)" query.
       (xterm--query "\e[>0c"
-                    ;; Some terminals (like OS X's Terminal.app) respond to
+                    ;; Some terminals (like macOS's Terminal.app) respond to
                     ;; this query as if it were a "Primary Device Attributes"
                     ;; query instead, so we should handle that too.
                     '(("\e[?" . xterm--version-handler)
diff --git a/lisp/textmodes/rst.el b/lisp/textmodes/rst.el
index 49809fab9e8..7161dd329ac 100644
--- a/lisp/textmodes/rst.el
+++ b/lisp/textmodes/rst.el
@@ -1227,7 +1227,7 @@ as well but give an additional message."
     ;;
     ;; The adjustment function that adorns or rotates a section title.
     (rst-define-key map [?\C-c ?\C-=] 'rst-adjust [?\C-c ?\C-a t])
-    (rst-define-key map [?\C-=] 'rst-adjust) ; Does not work on the Mac OSX and
+    (rst-define-key map [?\C-=] 'rst-adjust) ; Does not work on macOS and
 					     ; on consoles.
 
     ;; \C-c \C-a is the keymap for adornments.
diff --git a/lisp/vc/pcvs.el b/lisp/vc/pcvs.el
index 573feedd047..b0ad5ea588d 100644
--- a/lisp/vc/pcvs.el
+++ b/lisp/vc/pcvs.el
@@ -551,7 +551,7 @@ If non-nil, NEW means to create a new buffer no matter what."
 	       ;; is accessed via SSH, a bad interaction between libc,
 	       ;; CVS and SSH can lead to garbled output.
 	       ;; It might be a glibc-specific problem (but it can also happens
-	       ;; under Mac OS X, it seems).
+	       ;; under macOS, it seems).
 	       ;; It seems that using a pty can help circumvent the problem,
 	       ;; but at the cost of screwing up when the process thinks it
 	       ;; can ask for user input (such as password or host-key
@@ -696,7 +696,7 @@ SUBDIR is the subdirectory (if any) where this command was run.
 OLD-FIS is the list of fileinfos on which the cvs command was applied and
   which should be considered up-to-date if they are missing from the output."
   (when (eq system-type 'darwin)
-    ;; Fixup the ^D^H^H inserted at beginning of buffer sometimes on MacOSX
+    ;; Fixup the ^D^H^H inserted at beginning of buffer sometimes on macOS
     ;; because of the call to `process-send-eof'.
     (save-excursion
       (goto-char (point-min))
diff --git a/nextstep/INSTALL b/nextstep/INSTALL
index dd690abf1b1..3740346acd5 100644
--- a/nextstep/INSTALL
+++ b/nextstep/INSTALL
@@ -19,7 +19,7 @@ In the top-level directory, use:
 
   ./configure --with-ns
 
-(On Mac OS X, --with-ns is enabled by default.)
+(On macOS, --with-ns is enabled by default.)
 
 This will compile all the files, but emacs will not be able to be run except
 in -nw (terminal) mode.
diff --git a/nextstep/Makefile.in b/nextstep/Makefile.in
index 9aa034ad98d..d6e12825613 100644
--- a/nextstep/Makefile.in
+++ b/nextstep/Makefile.in
@@ -35,12 +35,12 @@ MKDIR_P = @MKDIR_P@
 
 ## Emacs.app.
 ns_appdir = @ns_appdir@
-## GNUstep: ns_appdir; OS X: ns_appdir/Contents/MacOS
+## GNUstep: ns_appdir; macOS: ns_appdir/Contents/MacOS
 ns_appbindir = @ns_appbindir@
 ## GNUstep/Emacs.base or Cocoa/Emacs.base.
 ns_appsrc = @ns_appsrc@
 ## GNUstep: GNUstep/Emacs.base/Resources/Info-gnustep.plist
-## OS X: Cocoa/Emacs.base/Contents/Info.plist
+## macOS: Cocoa/Emacs.base/Contents/Info.plist
 ns_check_file = @ns_appdir@/@ns_check_file@
 
 .PHONY: all
diff --git a/nextstep/README b/nextstep/README
index 7a1a0921cd8..6d37bb7b2d2 100644
--- a/nextstep/README
+++ b/nextstep/README
@@ -1,8 +1,8 @@
-  NS -- the Cocoa interface for OS X and compatible systems
-  ---------------------------------------------------------
+  NS -- the Cocoa interface for macOS and compatible systems
+  ----------------------------------------------------------
 
 This directory contains files needed to build Emacs on system based on
-NextStep (NS), including OS X (Mac) and GNUstep, using the Cocoa API.
+NextStep (NS), including macOS and GNUstep, using the Cocoa API.
 
 
   HISTORY
@@ -14,14 +14,14 @@ OpenStep and then Rhapsody, which became Mac OS X.  In 2004 it was
 adapted to GNUstep, a free OpenStep implementation, and in 2008 it was
 merged to the GNU Emacs trunk and released with Emacs 23.  Around the
 same time a separate Mac-only port using the Carbon APIs and
-descending from a 2001 MacOS 8/9 port of Emacs 21 was removed. (It
+descending from a 2001 Mac OS 8/9 port of Emacs 21 was removed. (It
 remains available externally under the name "mac".)
 
 
   OVERVIEW OF COCOA AND OBJECTIVE-C
 
 Cocoa is an API for the Objective-C language, an objective oriented
-superset of C.  Anybody with experience with iOS or modern OS X
+superset of C.  Anybody with experience with iOS or modern macOS
 application development should feel at home.
 
 A method call in Objective-C differs from most other languages in the
@@ -58,11 +58,11 @@ Classes are declared like the following:
 * Don't use macros and types intended for the XCode Interface Builder,
   like 'IBAction'.
 
-* The NS interface should work on all version of OS X from 10.6.8
-  (Snow Leopard) to the latest official release.
+* The NS interface should work on all version of macOS from Mac OS X
+  10.6.8 (Snow Leopard) to the latest official release.
 
-* Under OS X, it is possible to build Emacs using NS, X11, or console
-  only.  A new OS X feature should work in all appropriate builds.
+* Under macOS, it is possible to build Emacs using NS, X11, or console
+  only.  A new macOS feature should work in all appropriate builds.
 
 
   TRACING SUPPORT
@@ -76,7 +76,7 @@ uncomment the lines defining symbols starting with 'NSTRACE_GROUP'.
 
   GNUSTEP AND OTHER COMPATIBLE SYSTEMS
 
-The NS interface works on system compatible with OS X, for example
+The NS interface works on systems compatible with macOS, for example
 GNUstep.  Even though they are less frequently used, this is important
 for a number of reasons:
 
@@ -84,7 +84,7 @@ for a number of reasons:
   look-and-feel as the rest of the system.
 
 * This allows other Emacs developers to test their changes on the NS
-  interface without having access to an OS X machine.
+  interface without having access to a macOS machine.
 
 * If a feature in the NS interface work on free systems like GNUstep,
   this meets the FSF requirement that features in GNU software should
diff --git a/nextstep/templates/Emacs.desktop.in b/nextstep/templates/Emacs.desktop.in
index 170f195f270..4fed1e3b159 100644
--- a/nextstep/templates/Emacs.desktop.in
+++ b/nextstep/templates/Emacs.desktop.in
@@ -4,7 +4,7 @@ Type=Application
 Version=@version@
 Categories=GNUstep
 Name=Emacs
-Comment=GNU Emacs for NeXT/Open/GNUstep and OS X
+Comment=GNU Emacs for NeXT/Open/GNUstep and macOS
 Icon=emacs.tiff
 Exec=openapp Emacs.app
 #TryExec=Emacs.app
diff --git a/nextstep/templates/Info-gnustep.plist.in b/nextstep/templates/Info-gnustep.plist.in
index 679eb4fa435..1fd31849ab8 100644
--- a/nextstep/templates/Info-gnustep.plist.in
+++ b/nextstep/templates/Info-gnustep.plist.in
@@ -1,11 +1,11 @@
 {
-    ApplicationDescription = "GNU Emacs for GNUstep / OS X";
+    ApplicationDescription = "GNU Emacs for GNUstep / macOS";
     ApplicationIcon = emacs.tiff;
     ApplicationName = Emacs;
     ApplicationRelease = "@version@";
     Authors = (
 	"Adrian Robert (GNUstep)",
-	"Christophe de Dinechin (MacOS X)",
+	"Christophe de Dinechin (macOS)",
 	"Scott Bender (OpenStep)",
 	"Christian Limpach (NeXTstep)",
 	"Carl Edman (NeXTstep)",
diff --git a/nextstep/templates/Info.plist.in b/nextstep/templates/Info.plist.in
index dcd2fe34167..686b8047dfb 100644
--- a/nextstep/templates/Info.plist.in
+++ b/nextstep/templates/Info.plist.in
@@ -504,7 +504,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 		</dict>
 	</array>
 
-	<!-- Export definitions so that OS X understands about the file types -->
+	<!-- Export definitions so that macOS understands about the file types -->
 	<key>UTExportedTypeDeclarations</key>
 	<array>
 		<dict>
diff --git a/nt/README.W32 b/nt/README.W32
index d866d9fc7a6..b65a1de4eec 100644
--- a/nt/README.W32
+++ b/nt/README.W32
@@ -1,11 +1,12 @@
 Copyright (C) 2001-2016 Free Software Foundation, Inc.
 See the end of the file for license conditions.
 
-			   Emacs for Windows
+		Emacs version 25.1.50 for MS-Windows
 
   This README file describes how to set up and run a precompiled
-  distribution of GNU Emacs for Windows.  You can find the precompiled
-  distribution on the ftp.gnu.org server and its mirrors:
+  distribution of the latest version of GNU Emacs for MS-Windows.  You
+  can find the precompiled distribution on the ftp.gnu.org server and
+  its mirrors:
 
        ftp://ftp.gnu.org/gnu/emacs/windows/
 
@@ -15,19 +16,23 @@ See the end of the file for license conditions.
   Information on how to compile Emacs from sources on Windows is in
   the files README and INSTALL in the nt/ sub-directory of the
   top-level Emacs directory in the source distribution, as is this
-  file as README.precompiled.  If you received this file as part of
-  the Emacs source distribution, and are looking for information on
+  file under the name README.W32.  If you received this file as part
+  of the Emacs source distribution, and are looking for information on
   how to build Emacs on MS-Windows, please read those 2 files and not
   this one.
 
 * Preliminaries
 
   There are two binary distributions named
-  emacs-n-x86_64-w64-mingw32.zip and
-  emacs-n-i686-w64-mingw32.zip. These are for 64-bit and 32-bit
-  machines respectively.
+  emacs-VER-x86_64-w64-mingw32.zip and emacs-VER-i686-w64-mingw32.zip,
+  where VER is the Emacs version.  These are 64-bit and 32-bit builds,
+  respectively.  If you are running a 32-bit version of MS-Windows,
+  you need to install the 32-bit build; users of 64-bit Windows can
+  use either build, but we recommend to install the 64-bit one, as it
+  will be able to edit larger buffers and will generally run faster.
 
   The binary distribution has these top-level directories:
+
   + bin
   + libexec
   + share
@@ -36,23 +41,42 @@ See the end of the file for license conditions.
 * Setting up Emacs
 
   To install Emacs, simply unpack the binary package into a directory
-  of your choice. If you use File Explorer and "Extract" by default
-  this will be in a top-level directory with the same name as the zip
-  file.
+  of your choice.  If you use the Windows Explorer and its "Extract"
+  action, by default this will be in a top-level directory with the
+  same name as the zip file.
 
   We also provide a set of optional dependencies, in
-  emacs-25-x86_64-deps.zip or emacs-25-i686-deps.zip respectively,
-  which provide Emacs with an number of additional capabilities. To
-  add these, unpack them directly over the emacs directory structure.
+  emacs-MVER-x86_64-deps.zip or emacs-MVER-i686-deps.zip respectively,
+  where MVER is the major Emacs version that should use these
+  libraries.  These provide Emacs with a number of additional optional
+  capabilities, described in detail below.  To use these, unpack them
+  directly over the emacs directory structure.  Note that, if
+  extracting with the Windows Explorer, you will have to override the
+  directory where it wants to put the file with the same directory
+  where you extracted the Emacs binary package.
 
   Finally, and also optionally, you can run the program addpm.exe in
   the bin subdirectory which will place an icon for Emacs on the start
-  page.
-
-  Emacs is completely portable. You can create your own shortcut to
-  runemacs.exe and place this wherever you find it convenient, or
-  run it from a USB or network drive without copying or installing
-  anything on the machine itself.
+  page.  (This is no longer needed in latest versions of Emacs, so we
+  recommend you not do that, as running addpm.exe will insert entries
+  into the Registry which might get in the way if you upgrade to later
+  versions without updating those entries, or would like to uninstall
+  Emacs.)
+
+  Emacs is completely portable.  You can create your own shortcut to
+  runemacs.exe and place this wherever you find it convenient (the
+  desktop and/or the Taskbar), or run it from a USB or network drive
+  without copying or installing anything on the machine itself.
+
+* Prerequisites for Windows 9X
+
+  The 32-bit build supports MS-Windows 9X (Windows 95/98/Me).  To run
+  Emacs on these versions of Windows, you will need to have the
+  Microsoft Layer for Unicode (MSLU) installed.  It can be downloaded
+  from the Microsoft site, and comes in a form of a single dynamic
+  library called UNICOWS.DLL.  If this library is not accessible to
+  Emacs on Windows 9X, it will pop up a dialog saying that it cannot
+  find the UNICOWS library, and will refuse to start up.
 
 * Starting Emacs
 
@@ -66,7 +90,7 @@ See the end of the file for license conditions.
   If you want to use Emacs in tty or character mode within a command
   window, you can start it by typing "emacs -nw" at the command prompt.
   (Obviously, you need to ensure that the Emacs bin subdirectory is in
-  your PATH first, or specify the path to emacs.exe.)  The -nw
+  your Path first, or specify the path to emacs.exe.)  The -nw
   (non-windowed) mode of operation is most useful if you have a telnet
   server on your machine, allowing you to run Emacs remotely.
 
@@ -90,7 +114,8 @@ See the end of the file for license conditions.
   + emacsclientw.exe - A version of emacsclient that does not open
     a command-line window.
 
-  + addpm.exe - The installer that adds Emacs to "Start".
+  + addpm.exe - A basic installer that adds Emacs to "Start" menus and
+    adds Emacs-related entries to the Windows Registry.
 
   + ctags.exe, etags.exe - Tools for generating tag files.  See the
     `Tags' node of the Emacs manual.
@@ -124,26 +149,56 @@ See the end of the file for license conditions.
   + update-game-score.exe - A utility for updating the score files of
     Emacs games.
 
-* Optional Dependencies
+* Optional dependency libraries
 
   Emacs has built in support for XBM and PPM/PGM/PBM images, and the
   libXpm library is bundled, providing XPM support (required for color
-  toolbar icons and splash screen). Source for libXpm should be
+  toolbar icons and splash screen).  Source for libXpm should be
   available from the same place from which you got this binary
   distribution.
 
-  In addition, as described, there is a separate dependency bundle
-  providing support for many images formats, TLS, XML parsing and
-  compression.
+  Emacs has a number of optional features which need additional
+  libraries.  These are provided in a separate bundle of dependencies,
+  as described above, and enable support for the following:
+
+  - displaying inline images of many types (PNG, JPEG, GIF, TIFF, SVG)
+  - SSL/TLS secure network communications (HTTPS, IMAPS, etc.)
+  - HTML and XML parsing (necessary for the built-in EWW browser)
+  - built-in decompression of compressed text
+
+  The optional dependency libraries are in emacs-MVER-x86_64-deps.zip
+  (64-bit) and emacs-MVER-i686-deps.zip (32-bit), and their sources
+  are in emacs-MVER-deps-mingw-w64-src.zip, where MVER is the major
+  version of Emacs that should use these dependencies.  Note that a
+  64-bit Emacs will only work with the 64-bit dependencies, and the
+  32-bit Emacs only with the 32-bit dependencies.
+
+  Newer/updated builds for these optional libraries are available at
+  http://msys2.github.io/ and
+  http://sourceforge.net/projects/ezwinports/files/ (but you shouldn't
+  need these except in emergencies).
+
+  If you install the libraries in a directory different from where you
+  have the Emacs executable programs, we recommend to add the
+  directory with DLLs to your Path, so that Emacs will be able to find
+  those DLLs when needed.
 
-* Installing with an existing MSYS2 installation.
+* Installing Emacs with an existing MSYS2 installation
 
   You may also use Emacs with an existing MSYS2 installation by simply
-  unpacking the Emacs distribution over MSYS2. You can then use the
-  'pacman' utility to install dependencies. You should not use the
-  optional dependencies bundle, as this will overwrite MSYS2 files
-  (the dependency bundle derives from MSYS2, but may be a different
-  version).
+  unpacking the Emacs distribution over MSYS2.  You can then use the
+  'pacman' utility to install dependencies.  You should not use the
+  optional dependencies bundle from this site, as this will overwrite
+  MSYS2 files (the dependency bundle derives from MSYS2, but may be a
+  different version).
+
+  Some of the optional libraries need to be of certain versions to
+  work with your Emacs binary.  Make sure you install those versions
+  of dependencies, and no others.  Emacs variables such as
+  libpng-version and libjpeg-version tell what versions of the
+  corresponding libraries are expected by Emacs.  (We recommend that
+  you use the dependency bundle, where these issues are always
+  resolved.)
 
   To install the optional libraries, start the MSYS2 Bash window and
   type the following command:
@@ -153,17 +208,25 @@ See the end of the file for license conditions.
   where PACKAGES is the list of packages you want to install.  The
   full list is as follows:
 
-  mingw-w64-x86_64-giflib
-  mingw-w64-x86_64-gnutls
-  mingw-w64-x86_64-libjpeg-turbo
-  mingw-w64-x86_64-libpng
-  mingw-w64-x86_64-librsvg
-  mingw-w64-x86_64-libtiff
-  mingw-w64-x86_64-libxml2
-  mingw-w64-x86_64-xpm-nox
+    mingw-w64-x86_64-giflib
+    mingw-w64-x86_64-gnutls
+    mingw-w64-x86_64-libjpeg-turbo
+    mingw-w64-x86_64-libpng
+    mingw-w64-x86_64-librsvg
+    mingw-w64-x86_64-libtiff
+    mingw-w64-x86_64-libxml2
+    mingw-w64-x86_64-xpm-nox
 
-  You can type any subset of this list.  Once again, when asked
-  whether to proceed with installation, answer Y.
+  You can type any subset of this list.  When asked whether to proceed
+  with installation, answer Y.
+
+  Alternatively, you could install the packages manually from this
+  page:
+
+   https://sourceforge.net/projects/msys2/files/REPOS/MINGW/x86_64/
+
+  However, the packages there are not self-contained, so you will need
+  to manually download all their dependencies as well.
 
 * Uninstalling Emacs
 
@@ -184,6 +247,9 @@ See the end of the file for license conditions.
 
 * Troubleshooting
 
+  Some known problems and their solutions can be found in the file
+  etc\PROBLEMS in the unpacked Emacs distribution.
+
   Virus scanners
 
   Some virus scanners interfere with Emacs' use of subprocesses.  If you
@@ -191,6 +257,12 @@ See the end of the file for license conditions.
   McAfee's Vshield, turn off "Scan all files" (WinGuard) or "boot sector
   scanning" (McAfee exclusion properties).
 
+  Windows 9X
+
+  On Windows 9X, make sure you have the UNICOWS.DLL library either in
+  the same directory where you have emacs.exe or in the directory
+  where system-wide DLLs are kept.
+
 * Further information
 
   The Emacs User manual describes Windows-specific issues in the
@@ -206,17 +278,17 @@ See the end of the file for license conditions.
   In addition to the manual, there is a mailing list for help with
   Emacs here:
 
-       https://lists.gnu.org/mailman/listinfo/help-gnu-emacs
+       http://lists.gnu.org/mailman/listinfo/help-gnu-emacs
 
-  To ask questions on the mailing list, send email to
+  To ask questions on this mailing list, send email to
   help-gnu-emacs@gnu.org.
 
-  And a more specific one for issues related to the Windows port of
-  Emacs.  For information about the list, see this Web page:
+  A mailing list for issuesspecifically related to the MS-Windows port
+  of Emacs is here:
 
 	http://lists.gnu.org/mailman/listinfo/help-emacs-windows
 
-  To ask questions on the mailing list, send email to
+  To ask questions on this mailing list, send email to
   help-emacs-windows@gnu.org.
 
 * Reporting bugs
@@ -224,11 +296,11 @@ See the end of the file for license conditions.
   If you encounter a bug in this port of Emacs, we would like to hear
   about it.  First check the FAQ on the web page above to see if the bug
   is already known and if there are any workarounds.  Then check whether
-  the bug has something to do with code in your .emacs file, e.g. by
+  the bug has something to do with code in your `.emacs' file, e.g. by
   invoking Emacs with the "-Q" option.
 
   If you decide that it is a bug in Emacs, use the built in bug
-  reporting facility to report it (from the menu; Help -> Send Bug Report).
+  reporting facility to report it (from the menu: Help -> Send Bug Report).
   If you have not yet configured Emacs for mail, then when you press
   C-c C-c to send the report, it will ask you to paste the text of the
   report into your mail client.  If the bug is related to subprocesses,
diff --git a/src/coding.c b/src/coding.c
index b82d4f5cda9..feed9c8274c 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -122,7 +122,7 @@ END-OF-LINE FORMAT
   How text end-of-line is encoded depends on operating system.  For
   instance, Unix's format is just one byte of LF (line-feed) code,
   whereas DOS's format is two-byte sequence of `carriage-return' and
-  `line-feed' codes.  MacOS's format is usually one byte of
+  `line-feed' codes.  Classic Mac OS's format is usually one byte of
   `carriage-return'.
 
   Since text character encoding and end-of-line encoding are
diff --git a/src/conf_post.h b/src/conf_post.h
index 9c544e89e94..060b912fafb 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -186,7 +186,7 @@ You lose; /* Emacs for DOS must be compiled with DJGPP */
 #endif
 #endif  /* MSDOS */
 
-/* Mac OS X / GNUstep need a bit more pure memory.  Of the existing knobs,
+/* macOS / GNUstep need a bit more pure memory.  Of the existing knobs,
    SYSTEM_PURESIZE_EXTRA seems like the least likely to cause problems.  */
 #ifdef HAVE_NS
 #if defined NS_IMPL_GNUSTEP
diff --git a/src/emacs-module.c b/src/emacs-module.c
index 5075263edff..68aeb0ce704 100644
--- a/src/emacs-module.c
+++ b/src/emacs-module.c
@@ -147,8 +147,8 @@ static emacs_value const module_nil = 0;
    or a pointer to handle non-local exits.  The function must have an
    ENV parameter.  The function will return the specified value if a
    signal or throw is caught.  */
-// TODO: Have Fsignal check for CATCHER_ALL so we only have to install
-// one handler.
+/* TODO: Have Fsignal check for CATCHER_ALL so we only have to install
+   one handler.  */
 #define MODULE_HANDLE_NONLOCAL_EXIT(retval)                     \
   MODULE_SETJMP (CONDITION_CASE, module_handle_signal, retval); \
   MODULE_SETJMP (CATCHER_ALL, module_handle_throw, retval)
@@ -168,7 +168,7 @@ static emacs_value const module_nil = 0;
    code after the macro may longjmp back into the macro, which means
    its local variable C must stay live in later code.  */
 
-// TODO: Make backtraces work if this macros is used.
+/* TODO: Make backtraces work if this macros is used.  */
 
 #define MODULE_SETJMP_1(handlertype, handlerfunc, retval, c, dummy)	\
   if (module_non_local_exit_check (env) != emacs_funcall_exit_return)	\
diff --git a/src/emacs.c b/src/emacs.c
index d86c34fd1fd..efd4fa329df 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -2504,7 +2504,7 @@ Special values:
   `gnu'          compiled for a GNU Hurd system.
   `gnu/linux'    compiled for a GNU/Linux system.
   `gnu/kfreebsd' compiled for a GNU system with a FreeBSD kernel.
-  `darwin'       compiled for Darwin (GNU-Darwin, Mac OS X, ...).
+  `darwin'       compiled for Darwin (GNU-Darwin, macOS, ...).
   `ms-dos'       compiled as an MS-DOS application.
   `windows-nt'   compiled as a native W32 application.
   `cygwin'       compiled using the Cygwin library.
diff --git a/src/frame.c b/src/frame.c
index 3a2d009d325..b1d89f396ec 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -5110,7 +5110,7 @@ Setting this variable does not affect existing frames, only new ones.  */);
 	       doc: /* Default position of vertical scroll bars on this window-system.  */);
 #ifdef HAVE_WINDOW_SYSTEM
 #if defined (HAVE_NTGUI) || defined (NS_IMPL_COCOA) || (defined (USE_GTK) && defined (USE_TOOLKIT_SCROLL_BARS))
-  /* MS-Windows, Mac OS X, and GTK have scroll bars on the right by
+  /* MS-Windows, macOS, and GTK have scroll bars on the right by
      default.  */
   Vdefault_frame_scroll_bars = Qright;
 #else
diff --git a/src/gfilenotify.c b/src/gfilenotify.c
index 3b1f2fc516a..30d0753f7e7 100644
--- a/src/gfilenotify.c
+++ b/src/gfilenotify.c
@@ -105,7 +105,7 @@ dir_monitor_callback (GFileMonitor *monitor,
 
 	  /* Store it into the input event queue.  */
 	  kbd_buffer_store_event (&event);
-	  // XD_DEBUG_MESSAGE ("%s", XD_OBJECT_TO_STRING (event.arg));
+	  /* XD_DEBUG_MESSAGE ("%s", XD_OBJECT_TO_STRING (event.arg));  */
 	}
 
       /* Cancel monitor if file or directory is deleted.  */
diff --git a/src/gtkutil.c b/src/gtkutil.c
index 986eca85587..3d35a3dee81 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -191,7 +191,7 @@ xg_display_open (char *display_name, Display **dpy)
 {
   GdkDisplay *gdpy;
 
-  unrequest_sigio ();  // See comment in x_display_ok, xterm.c.
+  unrequest_sigio ();  /* See comment in x_display_ok, xterm.c.  */
   gdpy = gdk_display_open (display_name);
   request_sigio ();
   if (!gdpy_def && gdpy)
@@ -2386,7 +2386,7 @@ make_widget_for_menu_item (const char *utf8_label, const char *utf8_key)
    in the group.  On exit, *GROUP contains the radio item group.
 
    Unfortunately, keys don't line up as nicely as in Motif,
-   but the MacOS X version doesn't either, so I guess that is OK.  */
+   but the macOS version doesn't either, so I guess that is OK.  */
 
 static GtkWidget *
 make_menu_item (const char *utf8_label,
diff --git a/src/image.c b/src/image.c
index 1303a931263..d82fedb8dea 100644
--- a/src/image.c
+++ b/src/image.c
@@ -3718,7 +3718,7 @@ xpm_load (struct frame *f, struct image *img)
     }
 
 #ifdef USE_CAIRO
-  // Load very specific Xpm:s.
+  /* Load very specific Xpm:s.  */
   if (rc == XpmSuccess
       && img->ximg->format == ZPixmap
       && img->ximg->bits_per_pixel == 32
@@ -3742,7 +3742,7 @@ xpm_load (struct frame *f, struct image *img)
               int maskidx = mid ? i * img->mask_img->bytes_per_line + k/8 : 0;
               int mask = mid ? mid[maskidx] & (1 << (k % 8)) : 1;
 
-              if (mask) od[idx] = id[idx] + 0xff000000; // ff => full alpha
+              if (mask) od[idx] = id[idx] + 0xff000000; /* ff => full alpha */
               else od[idx] = bgcolor;
             }
         }
diff --git a/src/kqueue.c b/src/kqueue.c
index f45bd0c4c24..d1d0a612044 100644
--- a/src/kqueue.c
+++ b/src/kqueue.c
@@ -268,8 +268,6 @@ kqueue_compare_dir_list (Lisp_Object watch_object)
     report_file_error ("New list not empty", new_dl);
   if (! NILP (pending_dl))
     report_file_error ("Pending events list not empty", pending_dl);
-  //  if (! NILP (deleted_dl))
-  //    report_file_error ("Deleted events list not empty", deleted_dl);
 
   /* Replace old directory listing with the new one.  */
   XSETCDR (Fnthcdr (make_number (3), watch_object),
diff --git a/src/macfont.h b/src/macfont.h
index 6630fb526b7..8f734527a46 100644
--- a/src/macfont.h
+++ b/src/macfont.h
@@ -1,4 +1,4 @@
-/* Interface definition for Mac OSX Core text font backend.
+/* Interface definition for macOS Core text font backend.
    Copyright (C) 2009-2016 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
diff --git a/src/macfont.m b/src/macfont.m
index d9bad034fe9..3af9edc148a 100644
--- a/src/macfont.m
+++ b/src/macfont.m
@@ -1,4 +1,4 @@
-/* Font driver on Mac OSX Core text.
+/* Font driver on macOS Core text.
    Copyright (C) 2009-2016 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
@@ -1005,7 +1005,7 @@ macfont_set_family_cache (Lisp_Object symbol, CFStringRef string)
 and those start with ".".  NULL means the cache has been invalidated.
 Otherwise, the value is CFArray of CFStrings and the elements are
 sorted in the canonical order (CTFontManagerCompareFontFamilyNames on
-OS X 10.6 and later).  */
+Mac OS X 10.6 and later).  */
 
 static CFArrayRef macfont_available_families_cache = NULL;
 
@@ -4057,7 +4057,7 @@ mac_register_font_driver (struct frame *f)
 void
 syms_of_macfont (void)
 {
-  /* Core Text, for Mac OS X.  */
+  /* Core Text, for macOS.  */
   DEFSYM (Qmac_ct, "mac-ct");
   macfont_driver.type = Qmac_ct;
   register_font_driver (&macfont_driver, NULL);
diff --git a/src/nsfns.m b/src/nsfns.m
index b8264608b34..cfaaf53cbc6 100644
--- a/src/nsfns.m
+++ b/src/nsfns.m
@@ -1,4 +1,4 @@
-/* Functions for the NeXT/Open/GNUstep and MacOSX window system.
+/* Functions for the NeXT/Open/GNUstep and macOS window system.
 
 Copyright (C) 1989, 1992-1994, 2005-2006, 2008-2016 Free Software
 Foundation, Inc.
@@ -22,7 +22,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 Originally by Carl Edman
 Updated by Christian Limpach (chris@nice.ch)
 OpenStep/Rhapsody port by Scott Bender (sbender@harmony-ds.com)
-MacOSX/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
+macOS/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
 GNUstep port and post-20 update by Adrian Robert (arobert@cogsci.ucsd.edu)
 */
 
@@ -905,7 +905,7 @@ static void
 x_icon (struct frame *f, Lisp_Object parms)
 /* --------------------------------------------------------------------------
    Strangely-named function to set icon position parameters in frame.
-   This is irrelevant under OS X, but might be needed under GNUstep,
+   This is irrelevant under macOS, but might be needed under GNUstep,
    depending on the window manager used.  Note, this is not a standard
    frame parameter-setter; it is called directly from x-create-frame.
    -------------------------------------------------------------------------- */
@@ -2024,7 +2024,7 @@ DEFUN ("ns-list-services", Fns_list_services, Sns_list_services, 0, 0, 0,
 
   [svcs setAutoenablesItems: NO];
 #ifdef NS_IMPL_COCOA
-  [svcs update]; /* on OS X, converts from '/' structure */
+  [svcs update]; /* on macOS, converts from '/' structure */
 #endif
 
   ret = interpret_services_menu (svcs, Qnil, ret);
diff --git a/src/nsfont.m b/src/nsfont.m
index be7d2ec36b9..389d0ed7aa4 100644
--- a/src/nsfont.m
+++ b/src/nsfont.m
@@ -1,4 +1,4 @@
-/* Font back-end driver for the NeXT/Open/GNUstep and MacOSX window system.
+/* Font back-end driver for the NeXT/Open/GNUstep and macOS window system.
    See font.h
    Copyright (C) 2006-2016 Free Software Foundation, Inc.
 
@@ -497,7 +497,7 @@ static NSSet
 		  {
 		    NSCharacterSet *fset = [[fontMgr fontWithFamily: family
                         traits: 0 weight: 5 size: 12.0]	coveredCharacterSet];
-                    /* Some fonts on OS X, maybe many on GNUstep, return nil. */
+                    /* Some fonts on macOS, maybe many on GNUstep, return nil. */
                     if (fset == nil)
                       fset = [NSCharacterSet characterSetWithRange:
                                                NSMakeRange (0, 127)];
diff --git a/src/nsimage.m b/src/nsimage.m
index 6d1b3937f94..32bcea76ccd 100644
--- a/src/nsimage.m
+++ b/src/nsimage.m
@@ -1,4 +1,4 @@
-/* Image support for the NeXT/Open/GNUstep and MacOSX window system.
+/* Image support for the NeXT/Open/GNUstep and macOS window system.
    Copyright (C) 1989, 1992-1994, 2005-2006, 2008-2016 Free Software
    Foundation, Inc.
 
@@ -21,7 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 Originally by Carl Edman
 Updated by Christian Limpach (chris@nice.ch)
 OpenStep/Rhapsody port by Scott Bender (sbender@harmony-ds.com)
-MacOSX/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
+macOS/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
 GNUstep port and post-20 update by Adrian Robert (arobert@cogsci.ucsd.edu)
 */
 
diff --git a/src/nsmenu.m b/src/nsmenu.m
index 470d6d0dbcf..3e9887acf5d 100644
--- a/src/nsmenu.m
+++ b/src/nsmenu.m
@@ -1,4 +1,4 @@
-/* NeXT/Open/GNUstep and MacOSX Cocoa menu and toolbar module.
+/* NeXT/Open/GNUstep and macOS Cocoa menu and toolbar module.
    Copyright (C) 2007-2016 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
@@ -92,7 +92,7 @@ popup_activated (void)
 /* --------------------------------------------------------------------------
     Update menubar.  Three cases:
     1) ! deep_p, submenu = nil: Fresh switch onto a frame -- either set up
-       just top-level menu strings (OS X), or goto case (2) (GNUstep).
+       just top-level menu strings (macOS), or goto case (2) (GNUstep).
     2) deep_p, submenu = nil: Recompute all submenus.
     3) deep_p, submenu = non-nil: Update contents of a single submenu.
    -------------------------------------------------------------------------- */
@@ -577,7 +577,7 @@ x_activate_menubar (struct frame *f)
     return;
 /*fprintf (stderr, "Updating menu '%s'\n", [[self title] UTF8String]); NSLog (@"%@\n", event); */
 #ifdef NS_IMPL_GNUSTEP
-  /* Don't know how to do this for anything other than OSX >= 10.5
+  /* Don't know how to do this for anything other than Mac OS X 10.5 and later.
      This is wrong, as it might run Lisp code in the event loop.  */
   ns_update_menubar (frame, true, self);
 #endif
@@ -638,7 +638,7 @@ x_activate_menubar (struct frame *f)
 
       keyEq = [self parseKeyEquiv: wv->key];
 #ifdef NS_IMPL_COCOA
-      /* OS X just ignores modifier strings longer than one character */
+      /* macOS just ignores modifier strings longer than one character */
       if (keyEquivModMask == 0)
         title = [title stringByAppendingFormat: @" (%@)", keyEq];
 #endif
@@ -1048,9 +1048,9 @@ update_frame_tool_bar (struct frame *f)
       /* Check if this is a separator.  */
       if (EQ (TOOLPROP (TOOL_BAR_ITEM_TYPE), Qt))
         {
-          /* Skip separators.  Newer OSX don't show them, and on GNUstep they
-             are wide as a button, thus overflowing the toolbar most of
-             the time.  */
+          /* Skip separators.  Newer macOS don't show them, and on
+             GNUstep they are wide as a button, thus overflowing the
+             toolbar most of the time.  */
           continue;
         }
 
diff --git a/src/nsselect.m b/src/nsselect.m
index eba23932e65..b7c9148ee05 100644
--- a/src/nsselect.m
+++ b/src/nsselect.m
@@ -1,4 +1,4 @@
-/* NeXT/Open/GNUstep / MacOSX Cocoa selection processing for emacs.
+/* NeXT/Open/GNUstep / macOS Cocoa selection processing for emacs.
    Copyright (C) 1993-1994, 2005-2006, 2008-2016 Free Software
    Foundation, Inc.
 
@@ -21,7 +21,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 Originally by Carl Edman
 Updated by Christian Limpach (chris@nice.ch)
 OpenStep/Rhapsody port by Scott Bender (sbender@harmony-ds.com)
-MacOSX/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
+macOS/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
 GNUstep port and post-20 update by Adrian Robert (arobert@cogsci.ucsd.edu)
 */
 
diff --git a/src/nsterm.m b/src/nsterm.m
index 1b44a73cd8b..7e6ec85abf1 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -1,4 +1,4 @@
-/* NeXT/Open/GNUstep / MacOSX communication module.      -*- coding: utf-8 -*-
+/* NeXT/Open/GNUstep / macOS communication module.      -*- coding: utf-8 -*-
 
 Copyright (C) 1989, 1993-1994, 2005-2006, 2008-2016 Free Software
 Foundation, Inc.
@@ -22,7 +22,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 Originally by Carl Edman
 Updated by Christian Limpach (chris@nice.ch)
 OpenStep/Rhapsody port by Scott Bender (sbender@harmony-ds.com)
-MacOSX/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
+macOS/Aqua port by Christophe de Dinechin (descubes@earthlink.net)
 GNUstep port and post-20 update by Adrian Robert (arobert@cogsci.ucsd.edu)
 */
 
@@ -251,7 +251,7 @@ static unsigned convert_ns_to_X_keysym[] =
   0x1B,				0x1B   /* escape */
 };
 
-/* On OS X picks up the default NSGlobalDomain AppleAntiAliasingThreshold,
+/* On macOS picks up the default NSGlobalDomain AppleAntiAliasingThreshold,
    the maximum font size to NOT antialias.  On GNUstep there is currently
    no way to control this behavior. */
 float ns_antialias_threshold;
@@ -588,7 +588,7 @@ ns_load_path (void)
 
 void
 ns_init_locale (void)
-/* OS X doesn't set any environment variables for the locale when run
+/* macOS doesn't set any environment variables for the locale when run
    from the GUI. Get the locale from the OS and set LANG. */
 {
   NSLocale *locale = [NSLocale currentLocale];
@@ -597,7 +597,7 @@ ns_init_locale (void)
 
   @try
     {
-      /* It seems OS X should probably use UTF-8 everywhere.
+      /* It seems macOS should probably use UTF-8 everywhere.
          'localeIdentifier' does not specify the encoding, and I can't
          find any way to get the OS to tell us which encoding to use,
          so hard-code '.UTF-8'. */
@@ -719,7 +719,7 @@ ns_screen_margins (NSScreen *screen)
 
 
 /* A screen margin between 1 and DOCK_IGNORE_LIMIT (inclusive) is
-   assumed to contain a hidden dock.  OS X currently use 4 pixels for
+   assumed to contain a hidden dock.  macOS currently use 4 pixels for
    this, however, to be future compatible, a larger value is used.  */
 #define DOCK_IGNORE_LIMIT 6
 
@@ -732,7 +732,7 @@ reserved for an hidden dock.  */
 
   struct EmacsMargins margins = ns_screen_margins(screen);
 
-  /* OS X (currently) reserved 4 pixels along the edge where a hidden
+  /* macOS (currently) reserved 4 pixels along the edge where a hidden
      dock is located.  Unfortunately, it's not possible to find the
      location and information about if the dock is hidden.  Instead,
      it is assumed that if the margin of an edge is less than
@@ -749,7 +749,7 @@ reserved for an hidden dock.  */
     {
       margins.top = 0;
     }
-  /* Note: This doesn't occur in current versions of OS X, but
+  /* Note: This doesn't occur in current versions of macOS, but
      included for completeness and future compatibility.  */
   if (margins.bottom <= DOCK_IGNORE_LIMIT)
     {
@@ -1028,7 +1028,7 @@ ns_update_begin (struct frame *f)
 #ifdef NS_IMPL_COCOA
   if ([view isFullscreen] && [view fsIsNative])
   {
-    // Fix reappearing tool bar in fullscreen for OSX 10.7
+    // Fix reappearing tool bar in fullscreen for Mac OS X 10.7
     BOOL tbar_visible = FRAME_EXTERNAL_TOOL_BAR (f) ? YES : NO;
     NSToolbar *toolbar = [FRAME_NS_VIEW (f) toolbar];
     if (! tbar_visible != ! [toolbar isVisible])
@@ -1940,8 +1940,8 @@ ns_get_color (const char *name, NSColor **col)
     }
   else if ([nsname isEqualToString: @"ns_selection_fg_color"])
     {
-      /* NOTE: OSX applications normally don't set foreground selection, but
-         text may be unreadable if we don't.
+      /* NOTE: macOS applications normally don't set foreground
+         selection, but text may be unreadable if we don't.
       */
       if ((new = [NSColor selectedTextColor]) != nil)
         {
@@ -3879,7 +3879,7 @@ ns_send_appdefined (int value)
 #ifdef NS_IMPL_COCOA
   if (! send_appdefined)
     {
-      /* OSX 10.10.1 swallows the AppDefined event we are sending ourselves
+      /* OS X 10.10.1 swallows the AppDefined event we are sending ourselves
          in certain situations (rapid incoming events).
          So check if we have one, if not add one.  */
       NSEvent *appev = [NSApp nextEventMatchingMask:NSEventMaskApplicationDefined
@@ -4758,7 +4758,7 @@ ns_term_init (Lisp_Object display_name)
   [outerpool release];
   outerpool = [[NSAutoreleasePool alloc] init];
 
-  /* count object allocs (About, click icon); on OS X use ObjectAlloc tool */
+  /* count object allocs (About, click icon); on macOS use ObjectAlloc tool */
   /*GSDebugAllocationActive (YES); */
   block_input ();
 
@@ -4887,7 +4887,7 @@ ns_term_init (Lisp_Object display_name)
 
   ns_app_name = [[NSProcessInfo processInfo] processName];
 
-  /* Set up OS X app menu */
+  /* Set up macOS app menu */
 
   NSTRACE_MSG ("Menu init");
 
@@ -4959,7 +4959,7 @@ ns_term_init (Lisp_Object display_name)
          selector: @selector (trackingNotification:)
              name: NSMenuDidEndTrackingNotification object: mainMenu];
   }
-#endif /* MAC OS X menu setup */
+#endif /* macOS menu setup */
 
   /* Register our external input/output types, used for determining
      applicable services and also drag/drop eligibility. */
@@ -5187,7 +5187,7 @@ ns_term_shutdown (int sig)
 
 #ifdef NS_IMPL_COCOA
   /* If no dialog and none of our frames have focus and it is a move, skip it.
-     It is a mouse move in an auxiliary menu, i.e. on the top right on OSX,
+     It is a mouse move in an auxiliary menu, i.e. on the top right on macOS,
      such as Wifi, sound, date or similar.
      This prevents "spooky" highlighting in the frame under the menu.  */
   if (type == NSEventTypeMouseMoved && [NSApp modalWindow] == nil)
@@ -5722,7 +5722,7 @@ not_in_argv (NSString *arg)
 
   NSTRACE ("[EmacsView keyDown:]");
 
-  /* Rhapsody and OS X give up and down events for the arrow keys */
+  /* Rhapsody and macOS give up and down events for the arrow keys */
   if (ns_fake_keydown == YES)
     ns_fake_keydown = NO;
   else if ([theEvent type] != NSEventTypeKeyDown)
@@ -5956,7 +5956,7 @@ not_in_argv (NSString *arg)
 
 
 #ifdef NS_IMPL_COCOA
-/* Needed to pick up Ctrl-tab and possibly other events that OS X has
+/* Needed to pick up Ctrl-tab and possibly other events that Mac OS X
    decided not to send key-down for.
    See http://osdir.com/ml/editors.vim.mac/2007-10/msg00141.html
    This only applies on Tiger and earlier.
@@ -7121,8 +7121,8 @@ not_in_argv (NSString *arg)
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
       unsigned val = (unsigned)[NSApp presentationOptions];
 
-      // OSX 10.7 bug fix, the menu won't appear without this.
-      // val is non-zero on other OSX versions.
+      // Mac OS X 10.7 bug fix, the menu won't appear without this.
+      // val is non-zero on other macOS versions.
       if (val == 0)
         {
           NSApplicationPresentationOptions options
@@ -7546,7 +7546,7 @@ not_in_argv (NSString *arg)
   unblock_input ();
 
   /*
-    drawRect: may be called (at least in OS X 10.5) for invisible
+    drawRect: may be called (at least in Mac OS X 10.5) for invisible
     views as well for some reason.  Thus, do not infer visibility
     here.
 
@@ -8071,7 +8071,7 @@ not_in_argv (NSString *arg)
   [self setEnabled: YES];
 
   /* Ensure auto resizing of scrollbars occurs within the emacs frame's view
-     locked against the top and bottom edges, and right edge on OS X, where
+     locked against the top and bottom edges, and right edge on macOS, where
      scrollers are on right. */
 #ifdef NS_IMPL_GNUSTEP
   [self setAutoresizingMask: NSViewMaxXMargin | NSViewHeightSizable];
@@ -8732,14 +8732,14 @@ allowing it to be used at a lower level for accented character entry.");
 
   DEFVAR_LISP ("ns-auto-hide-menu-bar", ns_auto_hide_menu_bar,
                doc: /* Non-nil means that the menu bar is hidden, but appears when the mouse is near.
-Only works on OSX 10.6 or later.  */);
+Only works on Mac OS X 10.6 or later.  */);
   ns_auto_hide_menu_bar = Qnil;
 
   DEFVAR_BOOL ("ns-use-native-fullscreen", ns_use_native_fullscreen,
-     doc: /*Non-nil means to use native fullscreen on OSX >= 10.7.
+     doc: /*Non-nil means to use native fullscreen on Mac OS X 10.7 and later.
 Nil means use fullscreen the old (< 10.7) way.  The old way works better with
-multiple monitors, but lacks tool bar.  This variable is ignored on OSX < 10.7.
-Default is t for OSX >= 10.7, nil otherwise.  */);
+multiple monitors, but lacks tool bar.  This variable is ignored on
+Mac OS X < 10.7.  Default is t for 10.7 and later, nil otherwise.  */);
 #ifdef HAVE_NATIVE_FS
   ns_use_native_fullscreen = YES;
 #else
@@ -8754,9 +8754,9 @@ Default is nil.  */);
   ns_use_fullscreen_animation = NO;
 
   DEFVAR_BOOL ("ns-use-srgb-colorspace", ns_use_srgb_colorspace,
-     doc: /*Non-nil means to use sRGB colorspace on OSX >= 10.7.
+     doc: /*Non-nil means to use sRGB colorspace on Mac OS X 10.7 and later.
 Note that this does not apply to images.
-This variable is ignored on OSX < 10.7 and GNUstep.  */);
+This variable is ignored on Mac OS X < 10.7 and GNUstep.  */);
   ns_use_srgb_colorspace = YES;
 
   /* TODO: move to common code */
diff --git a/src/sysdep.c b/src/sysdep.c
index 55d29bcc814..892e97626bd 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -2426,7 +2426,7 @@ posix_close (int fd, int flag)
      closed, and retrying the close could inadvertently close a file
      descriptor allocated by some other thread.  In other systems
      (e.g., HP/UX) FD is not closed.  And in still other systems
-     (e.g., OS X, Solaris), maybe FD is closed, maybe not, and in a
+     (e.g., macOS, Solaris), maybe FD is closed, maybe not, and in a
      multithreaded program there can be no way to tell.
 
      So, in this case, pretend that the close succeeded.  This works
diff --git a/src/unexmacosx.c b/src/unexmacosx.c
index ea8e884f177..5584e693f75 100644
--- a/src/unexmacosx.c
+++ b/src/unexmacosx.c
@@ -1,4 +1,4 @@
-/* Dump Emacs in Mach-O format for use on Mac OS X.
+/* Dump Emacs in Mach-O format for use on macOS.
    Copyright (C) 2001-2016 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
@@ -24,7 +24,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    Mach-O format: the file loader.h, man pages for Mach-O and ld, old
    NEXTSTEP documents of the Mach-O format.  The tool otool dumps the
    mach header (-h option) and the load commands (-l option) in a
-   Mach-O file.  The tool nm on Mac OS X displays the symbol table in
+   Mach-O file.  The tool nm on macOS displays the symbol table in
    a Mach-O file.  For examples of unexec for the Mach-O format, see
    the file unexnext.c in the GNU Emacs distribution, the file
    unexdyld.c in the Darwin port of GNU Emacs 20.7, and unexdyld.c in
@@ -33,7 +33,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    Read that to see what they do.  This file was written completely
    from scratch, making use of information from the above sources.  */
 
-/* The Mac OS X implementation of unexec makes use of Darwin's `zone'
+/* The macOS implementation of unexec makes use of Darwin's `zone'
    memory allocator.  All calls to malloc, realloc, and free in Emacs
    are redirected to unexec_malloc, unexec_realloc, and unexec_free in
    this file.  When temacs is run, all memory requests are handled in
@@ -49,7 +49,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    block must be obtained by malloc and the old contents copied to
    it.  */
 
-/* Peculiarity of the Mach-O files generated by ld in Mac OS X
+/* Peculiarity of the Mach-O files generated by ld in macOS
    (possible causes of future bugs if changed).
 
    The file offset of the start of the __TEXT segment is zero.  Since
@@ -117,9 +117,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <assert.h>
 
-/* LC_DATA_IN_CODE is not defined in mach-o/loader.h on OS X 10.7.
+/* LC_DATA_IN_CODE is not defined in mach-o/loader.h on Mac OS X 10.7.
    But it is used if we build with "Command Line Tools for Xcode 4.5
-   (OS X Lion) - September 2012".  */
+   (Mac OS X Lion) - September 2012".  */
 #ifndef LC_DATA_IN_CODE
 #define LC_DATA_IN_CODE 0x29 /* table of non-instructions in __text */
 #endif
diff --git a/src/w32fns.c b/src/w32fns.c
index 1d83b02d629..8c8272b16d4 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -7328,7 +7328,7 @@ value of DIR as in previous invocations; this is standard Windows behavior.  */)
   } new_file_details_w;
 
 #ifdef NTGUI_UNICODE
-  wchar_t filename_buf_w[32*1024 + 1]; // NT kernel maximum
+  wchar_t filename_buf_w[32*1024 + 1]; /* NT kernel maximum */
   OPENFILENAMEW * file_details_w = &new_file_details_w.details;
   const int use_unicode = 1;
 #else /* not NTGUI_UNICODE */
diff --git a/src/xdisp.c b/src/xdisp.c
index 6e8af8aaf0a..c045ced000b 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -24565,7 +24565,7 @@ calc_pixel_width_or_height (double *res, struct it *it, Lisp_Object prop,
 	    }
 	  if (FRAME_WINDOW_P (it->f) && valid_xwidget_spec_p (prop))
 	    {
-              // TODO: Don't return dummy size.
+              /* TODO: Don't return dummy size.  */
               return OK_PIXELS (100);
             }
 #endif
diff --git a/src/xselect.c b/src/xselect.c
index 93b81b9fca1..b997cc887ef 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -693,7 +693,7 @@ x_reply_selection_request (struct selection_input_event *event,
 			     : format_bytes);
 	    XFlush (display);
 	    had_errors_p = x_had_errors_p (display);
-            // See comment above about property_change_reply.
+            /* See comment above about property_change_reply.  */
             set_property_change_object (cs->wait_object);
 	    unblock_input ();
 
@@ -1393,7 +1393,7 @@ receive_incremental_selection (struct x_display_info *dpyinfo,
   wait_object = expect_property_change (display, window, property,
 					PropertyNewValue);
   XFlush (display);
-  // See comment in x_reply_selection_request about property_change_reply.
+  /* See comment in x_reply_selection_request about property_change_reply.  */
   set_property_change_object (wait_object);
   unblock_input ();
 
@@ -1433,7 +1433,8 @@ receive_incremental_selection (struct x_display_info *dpyinfo,
       XDeleteProperty (display, window, property);
       wait_object = expect_property_change (display, window, property,
 					    PropertyNewValue);
-      // See comment in x_reply_selection_request about property_change_reply.
+      /* See comment in x_reply_selection_request about
+	 property_change_reply.  */
       set_property_change_object (wait_object);
       XFlush (display);
       unblock_input ();
diff --git a/src/xsmfns.c b/src/xsmfns.c
index a7ec8e0c7e2..95ede642130 100644
--- a/src/xsmfns.c
+++ b/src/xsmfns.c
@@ -170,7 +170,7 @@ smc_save_yourself_CB (SmcConn smcConn,
   char *smid_opt, *chdir_opt = NULL;
   Lisp_Object user_login_name = Fuser_login_name (Qnil);
 
-  // Must have these.
+  /* Must have these.  */
   if (! STRINGP (Vinvocation_name) || ! STRINGP (user_login_name))
     return;
 
diff --git a/src/xterm.c b/src/xterm.c
index d6e1fe2190c..bdc21e6de02 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -12063,7 +12063,7 @@ x_term_init (Lisp_Object display_name, char *xrm_option, char *resource_name)
 
 #else /* not USE_X_TOOLKIT */
   XSetLocaleModifiers ("");
-  unrequest_sigio ();  // See comment in x_display_ok.
+  unrequest_sigio ();  /* See comment in x_display_ok.  */
   dpy = XOpenDisplay (SSDATA (display_name));
   request_sigio ();
 #endif /* not USE_X_TOOLKIT */