diff --git a/doc/emacs/basic.texi b/doc/emacs/basic.texi
index b59ccf6ccfa..edb3d08f68d 100644
--- a/doc/emacs/basic.texi
+++ b/doc/emacs/basic.texi
@@ -131,12 +131,6 @@ Unicode), or a number with a specified radix, e.g., @code{#o23072}
 Manual}.  The command then inserts the corresponding character into
 the buffer.
 
-  In some contexts, if you type a quotation using grave accent and
-apostrophe @t{`like this'}, it is converted to a form @t{‘like this’}
-using single quotation marks.  Similarly, typing a quotation @t{``like
-this''} using double grave accent and apostrophe converts it to a form
-@t{“like this”} using double quotation marks.  @xref{Quotation Marks}.
-
   For example, the following all insert the same character:
 
 @example
@@ -151,6 +145,13 @@ this''} using double grave accent and apostrophe converts it to a form
   A numeric argument to @kbd{C-q} or @kbd{C-x 8 ...} specifies
 how many copies of the character to insert (@pxref{Arguments}).
 
+  In addition, in some contexts, if you type a quotation using grave
+accent and apostrophe @t{`like this'}, it is converted to a form
+@t{‘like this’} using single quotation marks, even without @kbd{C-x 8}
+commands.  Similarly, typing a quotation @t{``like this''} using
+double grave accent and apostrophe converts it to a form @t{“like
+this”} using double quotation marks.  @xref{Quotation Marks}.
+
 @node Moving Point
 @section Changing the Location of Point
 
@@ -711,6 +712,9 @@ where the two extra numbers give the smallest and largest character
 position that point is allowed to assume.  The characters between
 those two positions are the accessible ones.  @xref{Narrowing}.
 
+  Related, but different feature is @code{display-line-numbers-mode}
+(@pxref{Display Custom}).
+
 @node Arguments
 @section Numeric Arguments
 @cindex numeric arguments
diff --git a/doc/emacs/custom.texi b/doc/emacs/custom.texi
index c58cc7ebd70..5b2ab8280d1 100644
--- a/doc/emacs/custom.texi
+++ b/doc/emacs/custom.texi
@@ -127,7 +127,7 @@ brings up the customization buffer for that group.
 @kindex S-TAB @r{(customization buffer)}
 @findex widget-forward
 @findex widget-backward
-  In the customizable buffer, you can type @key{TAB}
+  In the customization buffer, you can type @key{TAB}
 (@code{widget-forward}) to move forward to the next button or editable
 field.  @kbd{S-@key{TAB}} (@code{widget-backward}) moves back to the
 previous button or editable field.
diff --git a/doc/emacs/emacs.texi b/doc/emacs/emacs.texi
index 09817080c58..5904740b1f6 100644
--- a/doc/emacs/emacs.texi
+++ b/doc/emacs/emacs.texi
@@ -1345,7 +1345,7 @@ for documentation.  @xref{GNU Free Documentation License}.}.
 @xref{Copying}.
 
 One way to get a copy of GNU Emacs is from someone else who has it.
-You need not ask for our permission to do so, or tell any one else;
+You need not ask for our permission to do so, or tell anyone else;
 just copy it.  If you have access to the Internet, you can get the
 latest distribution version of GNU Emacs by anonymous FTP; see
 @url{https://www.gnu.org/software/emacs} on our website for more
@@ -1361,7 +1361,7 @@ when you get it, not just free for the manufacturer.
 
 If you find GNU Emacs useful, please @strong{send a donation} to the
 Free Software Foundation to support our work.  Donations to the Free
-Software Foundation are tax deductible in the US@.  If you use GNU Emacs
+Software Foundation are tax-deductible in the US@.  If you use GNU Emacs
 at your workplace, please suggest that the company make a donation.
 To donate, see @url{https://my.fsf.org/donate/}.
 For other ways in which you can help, see
diff --git a/doc/emacs/entering.texi b/doc/emacs/entering.texi
index de0d7818099..2ff258ffb0c 100644
--- a/doc/emacs/entering.texi
+++ b/doc/emacs/entering.texi
@@ -18,10 +18,11 @@
 @cindex starting Emacs
 
   The usual way to invoke Emacs is with the shell command
-@command{emacs}.  From a terminal window running in the X Window
-System, you can run Emacs in the background with @command{emacs &};
-this way, Emacs won't tie up the terminal window, so you can use it to
-run other shell commands.
+@command{emacs}.  From a terminal window running a Unix shell in the X
+Window System, you can run Emacs in the background with @command{emacs
+&}; this way, Emacs won't tie up the terminal window, so you can use
+it to run other shell commands.  (For comparable methods of starting
+Emacs on MS-Windows, see @ref{Windows Startup}.)
 
 @cindex startup screen
   When Emacs starts up, the initial frame displays a special buffer
diff --git a/doc/emacs/msdos-xtra.texi b/doc/emacs/msdos-xtra.texi
index 43dc2654a67..541e29aa25f 100644
--- a/doc/emacs/msdos-xtra.texi
+++ b/doc/emacs/msdos-xtra.texi
@@ -380,7 +380,7 @@ using an actual directory named @file{/dev} on any disk.
 (@pxref{Printing}) and @code{ps-print-buffer} (@pxref{PostScript})
 @end ifnottex
 can work on MS-DOS by sending the output to one of the printer ports,
-if a Posix-style @code{lpr} program is unavailable.  The same Emacs
+if a POSIX-style @code{lpr} program is unavailable.  The same Emacs
 variables control printing on all systems, but in some cases they have
 different default values on MS-DOS.
 
@@ -567,7 +567,7 @@ asynchronous invocation on other platforms
 
   Instead of the Shell mode, which doesn't work on MS-DOS, you can use
 the @kbd{M-x eshell} command.  This invokes the Eshell package that
-implements a Posix-like shell entirely in Emacs Lisp.
+implements a POSIX-like shell entirely in Emacs Lisp.
 
   By contrast, Emacs compiled as a native Windows application
 @strong{does} support asynchronous subprocesses.
diff --git a/doc/emacs/msdos.texi b/doc/emacs/msdos.texi
index 25c3a567edd..9c47f47a736 100644
--- a/doc/emacs/msdos.texi
+++ b/doc/emacs/msdos.texi
@@ -129,7 +129,7 @@ window.  @xref{emacsclient Options}.
 @cindex text and binary files on MS-DOS/MS-Windows
 
   GNU Emacs uses newline characters to separate text lines.  This is the
-convention used on GNU, Unix, and other Posix-compliant systems.
+convention used on GNU, Unix, and other POSIX-compliant systems.
 
 @cindex end-of-line conversion on MS-DOS/MS-Windows
   By contrast, MS-DOS and MS-Windows normally use carriage-return linefeed,
@@ -770,7 +770,7 @@ more details.
   Printing commands, such as @code{lpr-buffer} (@pxref{Printing}) and
 @code{ps-print-buffer} (@pxref{PostScript}) work in MS-DOS and
 MS-Windows by sending the output to one of the printer ports, if a
-Posix-style @code{lpr} program is unavailable.  The same Emacs
+POSIX-style @code{lpr} program is unavailable.  The same Emacs
 variables control printing on all systems, but in some cases they have
 different default values on MS-DOS and MS-Windows.
 
diff --git a/doc/emacs/mule.texi b/doc/emacs/mule.texi
index fd25604c700..4989982eca0 100644
--- a/doc/emacs/mule.texi
+++ b/doc/emacs/mule.texi
@@ -1207,13 +1207,13 @@ using the internal Emacs representation.
 @cindex file-name encoding, MS-Windows
 @vindex w32-unicode-filenames
   When Emacs runs on MS-Windows versions that are descendants of the
-NT family (Windows 2000, XP, Vista, Windows 7, and Windows 8), the
-value of @code{file-name-coding-system} is largely ignored, as Emacs
-by default uses APIs that allow passing Unicode file names directly.
-By contrast, on Windows 9X, file names are encoded using
-@code{file-name-coding-system}, which should be set to the codepage
-(@pxref{Coding Systems, codepage}) pertinent for the current system
-locale.  The value of the variable @code{w32-unicode-filenames}
+NT family (Windows 2000, XP, Vista, Windows 7, and all the later
+versions), the value of @code{file-name-coding-system} is largely
+ignored, as Emacs by default uses APIs that allow passing Unicode file
+names directly.  By contrast, on Windows 9X, file names are encoded
+using @code{file-name-coding-system}, which should be set to the
+codepage (@pxref{Coding Systems, codepage}) pertinent for the current
+system locale.  The value of the variable @code{w32-unicode-filenames}
 controls whether Emacs uses the Unicode APIs when it calls OS
 functions that accept file names.  This variable is set by the startup
 code to @code{nil} on Windows 9X, and to @code{t} on newer versions of
@@ -1570,9 +1570,9 @@ used.  Some examples are:
 unpleasant results for characters for which they are used, and you may
 wish to instruct Emacs to completely ignore them while searching for a
 suitable font required to display a character.  You can do that by
-adding the offending fonts to the value of @code{face-ignored-fonts}
-variable, which is a list.  Here's an example to put in your
-@file{~/.emacs}:
+adding the offending fonts to the value of the variable
+@code{face-ignored-fonts}, which is a list.  Here's an example to put
+in your @file{~/.emacs}:
 
 @example
 (add-to-list 'face-ignored-fonts "Some Bad Font")
@@ -1673,10 +1673,10 @@ should use the command @kbd{M-x set-keyboard-coding-system} or
 customize the variable @code{keyboard-coding-system} to specify which
 coding system your keyboard uses (@pxref{Terminal Coding}).  Enabling
 this feature will probably require you to use @key{ESC} to type Meta
-characters; however, on a console terminal or in @code{xterm}, you can
-arrange for Meta to be converted to @key{ESC} and still be able to
-type 8-bit characters present directly on the keyboard or using
-@key{Compose} or @key{AltGr} keys.  @xref{User Input}.
+characters; however, on a console terminal or a terminal emulator such
+as @code{xterm}, you can arrange for Meta to be converted to @key{ESC}
+and still be able to type 8-bit characters present directly on the
+keyboard or using @key{Compose} or @key{AltGr} keys.  @xref{User Input}.
 
 @cindex @code{iso-transl} library
 @cindex compose character
@@ -1777,13 +1777,13 @@ for editing bidirectional text.
 @dfn{logical} (or @dfn{reading}) order: the buffer or string position
 of the first character you read precedes that of the next character.
 Reordering of bidirectional text into the @dfn{visual} order happens
-at display time.  As result, character positions no longer increase
+at display time.  As a result, character positions no longer increase
 monotonically with their positions on display.  Emacs implements the
 Unicode Bidirectional Algorithm (UBA) described in the Unicode
 Standard Annex #9, for reordering of bidirectional text for display.
 It deviates from the UBA only in how continuation lines are displayed
 when text direction is opposite to the base paragraph direction,
-e.g. when a long line of English text appears in a right-to-left
+e.g., when a long line of English text appears in a right-to-left
 paragraph.
 
 @vindex bidi-display-reordering
@@ -1835,12 +1835,13 @@ thin blank characters; on text terminals they display as blanks.
 
   Because characters are reordered for display, Emacs commands that
 operate in the logical order or on stretches of buffer positions may
-produce unusual effects.  For example, @kbd{C-f} and @kbd{C-b}
-commands move point in the logical order, so the cursor will sometimes
-jump when point traverses reordered bidirectional text.  Similarly, a
-highlighted region covering a contiguous range of character positions
-may look discontinuous if the region spans reordered text.  This is
-normal and similar to the behavior of other programs that support
-bidirectional text.  If you set @code{visual-order-cursor-movement} to
-a non-@code{nil} value, cursor motion by the arrow keys follows the
-visual order on screen (@pxref{Moving Point, visual-order movement}).
+produce unusual effects.  For example, the commands @kbd{C-f} and
+@kbd{C-b} move point in the logical order, so the cursor will
+sometimes jump when point traverses reordered bidirectional text.
+Similarly, a highlighted region covering a contiguous range of
+character positions may look discontinuous if the region spans
+reordered text.  This is normal and similar to the behavior of other
+programs that support bidirectional text.  If you set
+@code{visual-order-cursor-movement} to a non-@code{nil} value, cursor
+motion by the arrow keys follows the visual order on screen
+(@pxref{Moving Point, visual-order movement}).
diff --git a/doc/emacs/screen.texi b/doc/emacs/screen.texi
index d00b74fa656..fb4eff9711a 100644
--- a/doc/emacs/screen.texi
+++ b/doc/emacs/screen.texi
@@ -18,7 +18,7 @@ frames if you wish (@pxref{Frames}).
   Each frame consists of several distinct regions.  At the top of the
 frame is a @dfn{menu bar}, which allows you to access commands via a
 series of menus.  On a graphical display, directly below the menu bar
-is a @dfn{tool bar}, a row of icons that perform editing commands if
+is a @dfn{tool bar}, a row of icons that perform editing commands when
 you click on them.  At the very bottom of the frame is an @dfn{echo
 area}, where informative messages are displayed and where you enter
 information when Emacs asks for it.
diff --git a/doc/emacs/text.texi b/doc/emacs/text.texi
index 7e49a46b179..b9d3b7b94b4 100644
--- a/doc/emacs/text.texi
+++ b/doc/emacs/text.texi
@@ -101,7 +101,7 @@ Kill up to the end of a word (@code{kill-word}).
 @item M-@key{DEL}
 Kill back to the beginning of a word (@code{backward-kill-word}).
 @item M-@@
-Mark the end of the next word (@code{mark-word}).
+Set mark at the end of the next word (@code{mark-word}).
 @item M-t
 Transpose two words or drag a word across others
 (@code{transpose-words}).
diff --git a/doc/emacs/trouble.texi b/doc/emacs/trouble.texi
index 05114c376c9..2edeb05f9e0 100644
--- a/doc/emacs/trouble.texi
+++ b/doc/emacs/trouble.texi
@@ -806,7 +806,7 @@ stimulates the bug.
 @item
 If non-@acronym{ASCII} text or internationalization is relevant, the locale that
 was current when you started Emacs.  On GNU/Linux and Unix systems, or
-if you use a Posix-style shell such as Bash, you can use this shell
+if you use a POSIX-style shell such as Bash, you can use this shell
 command to view the relevant values:
 
 @smallexample
diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index 021a62a56ab..6a0312bd2f3 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -1170,14 +1170,14 @@ Sometimes file names or their parts need to be compared as strings, in
 which case it's important to know whether the underlying filesystem is
 case-insensitive.  This function returns @code{t} if file
 @var{filename} is on a case-insensitive filesystem.  It always returns
-@code{t} on MS-DOS and MS-Windows.  On Cygwin and Mac OS X,
+@code{t} on MS-DOS and MS-Windows.  On Cygwin and macOS,
 filesystems may or may not be case-insensitive, and the function tries
 to determine case-sensitivity by a runtime test.  If the test is
 inconclusive, the function returns @code{t} on Cygwin and @code{nil}
-on Mac OS X.
+on macOS.
 
 Currently this function always returns @code{nil} on platforms other
-than MS-DOS, MS-Windows, Cygwin, and Mac OS X.  It does not detect
+than MS-DOS, MS-Windows, Cygwin, and macOS.  It does not detect
 case-insensitivity of mounted filesystems, such as Samba shares or
 NFS-mounted Windows volumes.  On remote hosts, it assumes @code{t} for
 the @samp{smb} method.  For all other connection methods, runtime
@@ -1297,9 +1297,10 @@ The file's @acronym{GID}, likewise (@code{file-attribute-group-id}).
 The time of last access, as a list of four integers
 @code{(@var{sec-high} @var{sec-low} @var{microsec} @var{picosec})}
 (@code{file-attribute-access-time}).  (This is similar to the value of
-@code{current-time}; see @ref{Time of Day}.)  Note that on some
+@code{current-time}; see @ref{Time of Day}.)  The value is truncated
+to that of the filesystem's timestamp resolution; for example, on some
 FAT-based filesystems, only the date of last access is recorded, so
-this time will always hold the midnight of the day of last access.
+this time will always hold the midnight of the day of the last access.
 
 @cindex modification time of file
 @item
diff --git a/doc/lispref/loading.texi b/doc/lispref/loading.texi
index 0165d114a75..82c133de753 100644
--- a/doc/lispref/loading.texi
+++ b/doc/lispref/loading.texi
@@ -1151,7 +1151,7 @@ extension, a.k.a.@: ``suffix''.  This suffix is platform-dependent.
 
 @defvar module-file-suffix
 This variable holds the system-dependent value of the file-name
-extension of the module files.  Its value is @file{.so} on Posix hosts
+extension of the module files.  Its value is @file{.so} on POSIX hosts
 and @file{.dll} on MS-Windows.
 @end defvar
 
diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index 1a4e2db44a6..9352a929a7a 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -257,7 +257,7 @@ options were specified.
 
 @item
 If a daemon was requested, it calls @code{server-start}.
-(On Posix systems, if a background daemon was requested, it then
+(On POSIX systems, if a background daemon was requested, it then
 detaches from the controlling terminal.)  @xref{Emacs
 Server,,, emacs, The GNU Emacs Manual}.
 
@@ -888,7 +888,7 @@ IBM's AIX.
 Berkeley BSD and its variants.
 
 @item cygwin
-Cygwin, a Posix layer on top of MS-Windows.
+Cygwin, a POSIX layer on top of MS-Windows.
 
 @item darwin
 Darwin (macOS).
@@ -1325,13 +1325,13 @@ omitted or @code{nil}, the conversion uses Emacs's default time zone.
 If it is @code{t}, the conversion uses Universal Time.  If it is
 @code{wall}, the conversion uses the system wall clock time.  If it is
 a string, the conversion uses the time zone rule equivalent to setting
-@env{TZ} to that string.  If it is an integer @var{offset}, the
-conversion uses a fixed time zone with the given offset and a numeric
-abbreviation on POSIX-compatible platforms and an unspecified abbreviation
-on MS-Windows.  If it is a list (@var{offset} @var{abbr}), where
+@env{TZ} to that string.  If it is a list (@var{offset} @var{abbr}), where
 @var{offset} is an integer number of seconds east of Universal Time
 and @var{abbr} is a string, the conversion uses a fixed time zone with
-the given offset and abbreviation.
+the given offset and abbreviation.  An integer @var{offset} is treated
+as if it were (@var{offset} @var{abbr}), where @var{abbr} is a numeric
+abbreviation on POSIX-compatible platforms and is unspecified on
+MS-Windows.
 
 @defun current-time-zone &optional time zone
 @cindex time zone, current
@@ -1488,6 +1488,7 @@ This is a synonym for @samp{%x %X}.
 @item %C
 This stands for the century, that is, the year divided by 100,
 truncated toward zero.
+The default field width is 2.
 @item %d
 This stands for the day of month, zero-padded.
 @item %D
@@ -2398,7 +2399,7 @@ Emacs is restarted by the session manager.
 
 Emacs is able to send @dfn{notifications} on systems that support the
 freedesktop.org Desktop Notifications Specification and on MS-Windows.
-In order to use this functionality on Posix hosts, Emacs must have
+In order to use this functionality on POSIX hosts, Emacs must have
 been compiled with D-Bus support, and the @code{notifications} library
 must be loaded.  @xref{Top, , D-Bus,dbus,D-Bus integration in Emacs}.
 The following function is supported when D-Bus support is available:
diff --git a/doc/lispref/streams.texi b/doc/lispref/streams.texi
index a25a5bfe84a..bd7dc2d9af3 100644
--- a/doc/lispref/streams.texi
+++ b/doc/lispref/streams.texi
@@ -344,7 +344,7 @@ When reading or writing from the standard input/output streams of the
 Emacs process in batch mode, it is sometimes required to make sure any
 arbitrary binary data will be read/written verbatim, and/or that no
 translation of newlines to or from CR-LF pairs is performed.  This
-issue does not exist on Posix hosts, only on MS-Windows and MS-DOS@.
+issue does not exist on POSIX hosts, only on MS-Windows and MS-DOS@.
 The following function allows you to control the I/O mode of any
 standard stream of the Emacs process.
 
@@ -354,7 +354,7 @@ non-@code{nil}, switch to binary mode, otherwise switch to text mode.
 The value of @var{stream} can be one of @code{stdin}, @code{stdout},
 or @code{stderr}.  This function flushes any pending output data of
 @var{stream} as a side effect, and returns the previous value of I/O
-mode for @var{stream}.  On Posix hosts, it always returns a
+mode for @var{stream}.  On POSIX hosts, it always returns a
 non-@code{nil} value and does nothing except flushing pending output.
 @end defun
 
@@ -707,7 +707,7 @@ indent and fill the object to make it more readable for humans.
 
 If you need to use binary I/O in batch mode, e.g., use the functions
 described in this section to write out arbitrary binary data or avoid
-conversion of newlines on non-Posix hosts, see @ref{Input Functions,
+conversion of newlines on non-POSIX hosts, see @ref{Input Functions,
 set-binary-mode}.
 
 @node Output Variables
diff --git a/doc/misc/calc.texi b/doc/misc/calc.texi
index 1144f2843cd..40b16b0f3c9 100644
--- a/doc/misc/calc.texi
+++ b/doc/misc/calc.texi
@@ -29128,7 +29128,7 @@ the X window system or MS-Windows, Calc will configure GNUPLOT for you
 automatically.  If you have GNUPLOT 3.0 or later and you are using a
 Unix or GNU system without X, Calc will configure GNUPLOT to display
 graphs using simple character graphics that will work on any
-Posix-compatible terminal.
+POSIX-compatible terminal.
 
 @menu
 * Basic Graphics::
diff --git a/doc/misc/org.texi b/doc/misc/org.texi
index 762dfafdda7..aa3b029ab7c 100644
--- a/doc/misc/org.texi
+++ b/doc/misc/org.texi
@@ -6752,7 +6752,7 @@ 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/lisp/emacs-lisp/rx.el b/lisp/emacs-lisp/rx.el
index 37aa25b556d..c4f6d4f70ea 100644
--- a/lisp/emacs-lisp/rx.el
+++ b/lisp/emacs-lisp/rx.el
@@ -57,7 +57,6 @@
 ;; (rx (and line-start (0+ (in "a-z"))))
 ;;
 ;; "\n[^ \t]"
-;; (rx (and "\n" (not blank))), or
 ;; (rx (and "\n" (not (any " \t"))))
 ;;
 ;; "\\*\\*\\* EOOH \\*\\*\\*\n"
@@ -74,9 +73,9 @@
 ;; "^content-transfer-encoding:\\(\n?[\t ]\\)*quoted-printable\\(\n?[\t ]\\)*"
 ;; (rx (and line-start
 ;;          "content-transfer-encoding:"
-;;          (+ (? ?\n)) blank
+;;          (+ (? ?\n)) (any " \t")
 ;;	    "quoted-printable"
-;;	    (+ (? ?\n)) blank))
+;;	    (+ (? ?\n)) (any " \t"))
 ;;
 ;; (concat "^\\(?:" something-else "\\)")
 ;; (rx (and line-start (eval something-else))), statically or
@@ -962,7 +961,11 @@ CHAR
      matches 0 through 9, a through f and A through F.
 
 `blank'
-     matches space and tab only.
+     matches horizontal whitespace, as defined by Annex C of the
+     Unicode Technical Standard #18.  In particular, it matches
+     spaces, tabs, and other characters whose Unicode
+     `general-category' property indicates they are spacing
+     separators.
 
 `graphic', `graph'
      matches graphic characters--everything except whitespace, ASCII