Fix some Texinfo markup in manuals

* doc/emacs/macos.texi (Mac / GNUstep Customization):
* doc/lispintro/emacs-lisp-intro.texi (condition-case):
* doc/lispref/control.texi (pcase Macro):
* doc/lispref/debugging.texi (Internals of Debugger):
* doc/lispref/internals.texi (Building Emacs):
* doc/lispref/modes.texi (Imenu):
(Parser-based Font Lock, Parser-based Indentation):
* doc/lispref/parsing.texi (Retrieving Nodes, Tree-sitter C API):
* doc/lispref/processes.texi (Network, Bindat Types):
* doc/lispref/searching.texi (Rx Functions):
* doc/lispref/text.texi (Replacing):
* doc/lispref/windows.texi (Textual Scrolling):
* doc/misc/calc.texi (Killing From Stack, Customizing Calc):
* doc/misc/cc-mode.texi (Misc Font Locking, List Line-Up):
* doc/misc/ede.texi (ede-cpp-root-project)
(ede-proj-target-makefile, ede-sourcecode):
* doc/misc/ert.texi (Running Tests in Batch Mode):
* doc/misc/eudc.texi (Emacs-only Configuration, The Server Hotlist):
* doc/misc/eww.texi (Advanced):
* doc/misc/flymake.texi (Starting Flymake)
(Proc customization variables):
* doc/misc/tramp.texi (File name completion):
* doc/misc/gnus.texi (Summary Buffer Lines, Gnus Registry Setup)
(Fancy splitting to parent, Customizing the IMAP Connection)
(Mail Source Specifiers, Agent as Cache): Consistently mark up nil
and t as @code.  Also fix the markup and wording of some surrounding
text (bug#64016).

* doc/lispref/display.texi (SVG Images, Icons):
* doc/lispref/modes.texi (Customizing Keywords): Prefer ASCII
apostrophe over Unicode right single quotation mark.

doc/emacs/macos.texi

@@ -177,10 +177,10 @@ These variables only apply to macOS 10.7 (Lion) and above.
 @vindex ns-use-mwheel-acceleration
 @item ns-use-mwheel-acceleration
 This variable controls whether Emacs ignores the system mousewheel
-acceleration.  When nil each `click' of the mousewheel will correspond
+acceleration.  When @code{nil} each `click' of the mousewheel will
-exactly with one mousewheel event.  When non-@code{nil}, the default, each
+correspond exactly with one mousewheel event.  When non-@code{nil},
-`click' may correspond with more than one mousewheel event, depending
+the default, each `click' may correspond with more than one mousewheel
-on the user's input.
+event, depending on the user's input.
 
 @vindex ns-use-mwheel-momentum
 @item ns-use-mwheel-momentum
@@ -194,8 +194,8 @@ while after the user has lifted their fingers off the trackpad.
 This variable controls the sensitivity of scrolling with the trackpad.
 Apple trackpads scroll by pixels, not lines, so Emacs converts the
 system's pixel values into lines.  When set to a number, this variable
-sets the number of pixels Emacs will consider as one line.  When nil
+sets the number of pixels Emacs will consider as one line.  When
-or a non-number the default line height is used.
+@code{nil} or a non-number the default line height is used.
 
 Setting a lower number makes the trackpad more sensitive, and a higher
 number makes the trackpad less sensitive.

doc/lispintro/emacs-lisp-intro.texi

@@ -8115,10 +8115,9 @@ than one error handler.  When an error occurs, the first applicable
 handler is run.
 
 Lastly, the first argument to the @code{condition-case} expression,
-the @var{var} argument, is sometimes bound to a variable that
+the @var{var} argument, is sometimes bound to a variable that contains
-contains information about the error.  However, if that argument is
+information about the error.  However, if that argument is @code{nil},
-nil, as is the case in @code{kill-region}, that information is
+as is the case in @code{kill-region}, that information is discarded.
-discarded.
 
 @need 1200
 In brief, in the @code{kill-region} function, the code

doc/lispref/control.texi

@@ -694,7 +694,7 @@ contain the following constructs:
 @item (let @var{ref} @var{rx-expr}@dots{})
 Bind the symbol @var{ref} to a submatch that matches
 @var{rx-expr}@enddots{}.  @var{ref} is bound in @var{body-forms} to
-the string of the submatch or nil, but can also be used in
+the string of the submatch or @code{nil}, but can also be used in
 @code{backref}.
 
 @item (backref @var{ref})

doc/lispref/debugging.texi

@@ -740,7 +740,7 @@ of @code{debug} (@pxref{Invoking the Debugger}).
 @cindex call stack
 This function prints a trace of Lisp function calls currently active.
 The trace is identical to the one that @code{debug} would show in the
-@file{*Backtrace*} buffer.  The return value is always nil.
+@file{*Backtrace*} buffer.  The return value is always @code{nil}.
 
 In the following example, a Lisp expression calls @code{backtrace}
 explicitly.  This prints the backtrace to the stream

doc/lispref/display.texi

@@ -6530,7 +6530,7 @@ specified, draw a polyline.
 @deffn Command horizontal-lineto x-coordinates
 Draw a horizontal line from the current point to the first element in
 @var{x-coordinates}.  Specifying multiple coordinates is possible,
-although usually this doesn’t make sense.
+although this usually doesn't make sense.
 
 @lisp
 (svg-path svg '((moveto ((100 . 200)))
@@ -6554,7 +6554,7 @@ Using the first element in @var{coordinate-sets}, draw a cubic Bézier
 curve from the current point.  If there are multiple coordinate sets,
 draw a polybezier.  Each coordinate set is a list of the form
 @code{(@var{x1} @var{y1} @var{x2} @var{y2} @var{x} @var{y})}, where
-@w{(@var{x}, @var{y})} is the curve’s end point.  @w{(@var{x1},
+@w{(@var{x}, @var{y})} is the curve's end point.  @w{(@var{x1},
 @var{y1})} and @w{(@var{x2}, @var{y2})} are control points at the
 beginning and at the end, respectively.
 
@@ -6571,7 +6571,7 @@ Using the first element in @var{coordinate-sets}, draw a cubic Bézier
 curve from the current point.  If there are multiple coordinate sets,
 draw a polybezier.  Each coordinate set is a list of the form
 @code{(@var{x2} @var{y2} @var{x} @var{y})}, where @w{(@var{x},
-@var{y})} is the curve’s end point and @w{(@var{x2}, @var{y2})} is the
+@var{y})} is the curve's end point and @w{(@var{x2}, @var{y2})} is the
 corresponding control point.  The first control point is the
 reflection of the second control point of the previous command
 relative to the current point, if that command was @command{curveto}
@@ -6591,7 +6591,7 @@ Using the first element in @var{coordinate-sets}, draw a quadratic
 Bézier curve from the current point.  If there are multiple coordinate
 sets, draw a polybezier.  Each coordinate set is a list of the form
 @code{(@var{x1} @var{y1} @var{x} @var{y})}, where @w{(@var{x},
-@var{y})} is the curve’s end point and @w{(@var{x1}, @var{y1})} is the
+@var{y})} is the curve's end point and @w{(@var{x1}, @var{y1})} is the
 control point.
 
 @lisp
@@ -6608,7 +6608,7 @@ control point.
 Using the first element in @var{coordinate-sets}, draw a quadratic
 Bézier curve from the current point.  If there are multiple coordinate
 sets, draw a polybezier.  Each coordinate set is a list of the form
-@code{(@var{x} @var{y})}, where @w{(@var{x}, @var{y})} is the curve’s
+@code{(@var{x} @var{y})}, where @w{(@var{x}, @var{y})} is the curve's
 end point.  The control point is the reflection of the control point
 of the previous command relative to the current point, if that command
 was @command{quadratic-bezier-curveto} or
@@ -7269,7 +7269,7 @@ window.
 @item :width
 This is only valid for @code{image} icons, and can be either a number
 (which specifies the width in pixels), or the symbol @code{font},
-which will use the width in pixels of the current buffer’s default
+which will use the width in pixels of the current buffer's default
 face font.
 @end table
 

doc/lispref/internals.texi

@@ -248,7 +248,7 @@ time it took to restore the Emacs state.  The value is an alist
 where @var{file} is the name of the dump file, and @var{time} is the
 time in seconds it took to restore the state from the dump file.
 If the current session was not restored from a dump file, the
-value is nil.
+value is @code{nil}.
 @end defun
 
 @node Pure Storage

doc/lispref/modes.texi

@@ -2921,13 +2921,13 @@ nodes that belong to @var{category}.  @var{pred} should be either
 return non-@code{nil} if the node is a valid node for @var{category},
 or @code{nil} if not.
 
-@var{category} could also be @code{nil}.  In which case the entries
+@var{category} could also be @code{nil}, in which case the entries
 matched by @var{regexp} and @var{pred} are not grouped under
 @var{category}.
 
-@var{name-fn} should be either @var{nil} or a function that takes a
+@var{name-fn} should be either @code{nil} or a function that takes a
 defun node and returns the name of that defun, e.g., the function name
-for a function definition.  If @var{name-fn} is @var{nil},
+for a function definition.  If @var{name-fn} is @code{nil},
 @code{treesit-defun-name} (@pxref{Tree-sitter Major Modes}) is used
 instead.
 
@@ -3446,7 +3446,7 @@ This condition matches any element of Font Lock keywords for which
 non-@code{nil}.
 
 @item @code{(not @var{condition})}
-This matches if @var{condition} doesn’t.
+This matches if @var{condition} doesn't.
 
 @item @code{(and @var{condition} @dots{})}
 This matches if each of the @var{condition}s matches.
@@ -4145,9 +4145,9 @@ Other keywords are optional:
 
 @multitable @columnfractions .15 .15 .6
 @headitem Keyword @tab Value @tab Description
-@item @code{:override} @tab nil
+@item @code{:override} @tab @code{nil}
 @tab If the region already has a face, discard the new face
-@item @tab t @tab Always apply the new face
+@item @tab @code{t} @tab Always apply the new face
 @item @tab @code{append} @tab Append the new face to existing ones
 @item @tab @code{prepend} @tab Prepend the new face to existing ones
 @item @tab @code{keep} @tab Fill-in regions without an existing face
@@ -5153,10 +5153,10 @@ This anchor is a function that is called with 3 arguments: @var{node},
 @var{parent}, and @var{bol}.  It tries to go to the beginning of the
 previous non-empty line, and matches @code{adaptive-fill-regexp}.  If
 there is a match, this function returns the end of the match,
-otherwise it returns nil.  However, if the current line begins with a
+otherwise it returns @code{nil}.  However, if the current line begins
-prefix (e.g., ``-''), return the beginning of the prefix of the
+with a prefix (e.g., ``-''), return the beginning of the prefix of the
-previous line instead, so that the two prefixes aligns.  This anchor
+previous line instead, so that the two prefixes align.  This anchor is
-is useful for a @code{indent-relative}-like indent behavior for block
+useful for an @code{indent-relative}-like indent behavior for block
 comments.
 
 @end ftable

doc/lispref/parsing.texi

@@ -656,7 +656,7 @@ it, or query for information about this node.
 This function returns the immediate parent of @var{node}.
 
 If @var{node} is more than 1000 levels deep in a parse tree, the
-return value is undefined.  Currently it returns @var{nil}, but that
+return value is undefined.  Currently it returns @code{nil}, but that
 could change in the future.
 @end defun
 
@@ -842,7 +842,7 @@ the number of levels to go down from @var{root}.  If @var{depth} is
 
 Each node in the returned tree looks like
 @w{@code{(@var{tree-sitter-node} . (@var{child} @dots{}))}}.  The
-@var{tree-sitter-node} of the root of this tree will be nil if
+@var{tree-sitter-node} of the root of this tree will be @code{nil} if
 @var{root} doesn't match @var{predicate}.  If no node matches
 @var{predicate}, the function returns @code{nil}.
 @end defun
@@ -866,7 +866,7 @@ the argument and returns a boolean that indicates a match.  If no
 parent satisfies @var{pred}, this function returns @code{nil}.
 
 Normally this function only looks at the parents of @var{node} but not
-@var{node} itself. But if @var{include-node} is non-@var{nil}, this
+@var{node} itself.  But if @var{include-node} is non-@code{nil}, this
 function returns @var{node} if @var{node} satisfies @var{pred}.
 @end defun
 
@@ -1880,7 +1880,7 @@ convenient and idiomatic:
 Instead of using byte positions, the Emacs Lisp API uses character
 positions.
 @item
-Null nodes are converted to nil.
+Null nodes are converted to @code{nil}.
 @end itemize
 
 Below is the correspondence between all C API functions and their

doc/lispref/processes.texi

@@ -2662,7 +2662,7 @@ naming the certificate key file and certificate file itself, or
 Library}).  Only used for @acronym{TLS} or @acronym{STARTTLS}.  To
 enable automatic queries of @code{auth-source} when
 @code{:client-certificate} is not specified customize
-@code{network-stream-use-client-certificates} to t.
+@code{network-stream-use-client-certificates} to @code{t}.
 
 @item :return-list @var{cons-or-nil}
 The return value of this function.  If omitted or @code{nil}, return a
@@ -3575,7 +3575,7 @@ and @code{#x1c} @code{#x28} to @w{@code{(3 5 10 11 12)}}.
 @item fill @var{len}
 @var{len} bytes used as a mere filler.  In packing, these bytes are
 left unchanged, which normally means they remain zero.
-When unpacking, this just returns nil.
+When unpacking, this just returns @code{nil}.
 
 @item align @var{len}
 Same as @code{fill} except the number of bytes is that needed to skip

doc/lispref/searching.texi

@@ -1568,7 +1568,7 @@ used, a Lisp expression that evaluates to a string.  Example:
 
 @defun rx-to-string rx-expr &optional no-group
 Translate @var{rx-expr} to a string regexp which is returned.
-If @var{no-group} is absent or nil, bracket the result in a
+If @var{no-group} is absent or @code{nil}, bracket the result in a
 non-capturing group, @samp{\(?:@dots{}\)}, if necessary to ensure that
 a postfix operator appended to it will apply to the whole expression.
 Example:

doc/lispref/text.texi

@@ -4764,9 +4764,9 @@ and exceeded, it will fall back to @code{delete-region} and
 the actual costs exceed this limit, heuristics are used to provide a
 faster but suboptimal solution.  The default value is 1000000.
 
-@code{replace-buffer-contents} returns t if a non-destructive
+@code{replace-buffer-contents} returns @code{t} if a non-destructive
 replacement could be performed.  Otherwise, i.e., if @var{max-secs}
-was exceeded, it returns nil.
+was exceeded, it returns @code{nil}.
 @end deffn
 
 @defun replace-region-contents beg end replace-fn &optional max-secs max-costs

doc/lispref/windows.texi

@@ -5569,7 +5569,7 @@ non-@code{nil}, this function may redraw the frame, according to the
 value of @code{recenter-redisplay}.  Thus, omitting the second
 argument can be used to countermand the effect of
 @code{recenter-redisplay} being non-@code{nil}.  Interactive calls
-pass non-‘nil’ for @var{redisplay}.
+pass non-@code{nil} for @var{redisplay}.
 
 When @code{recenter} is called interactively, @var{count} is the raw
 prefix argument.  Thus, typing @kbd{C-u} as the prefix sets the

doc/misc/calc.texi

@@ -29875,10 +29875,10 @@ with no argument copies only the number itself into the kill ring, whereas
 @kbd{C-k} with a prefix argument of 1 copies the number with its trailing
 newline.
 
-You can customize @code{calc-kill-line-numbering} to nil to exclude
+You can customize @code{calc-kill-line-numbering} to @code{nil} to
-line numbering from kills and copies made by @code{calc-kill} and
+exclude line numbering from kills and copies made by @code{calc-kill}
-@code{calc-copy-as-kill}.  This option does not affect calc kill and
+and @code{calc-copy-as-kill}.  This option does not affect calc kill
-copy commands which operate on the region, as that would not make
+and copy commands which operate on the region, as that would not make
 sense.
 
 @node Yanking Into Stack
@@ -35590,11 +35590,11 @@ The default value of @code{calc-note-threshold} is 1.
 See @ref{Displaying Selections}.@*
 The variable @code{calc-highlight-selections-with-faces}
 determines how selected sub-formulas are distinguished.
-If @code{calc-highlight-selections-with-faces} is nil, then
+If @code{calc-highlight-selections-with-faces} is @code{nil}, then
 a selected sub-formula is distinguished either by changing every
 character not part of the sub-formula with a dot or by changing every
 character in the sub-formula with a @samp{#} sign.
-If @code{calc-highlight-selections-with-faces} is t,
+If @code{calc-highlight-selections-with-faces} is @code{t},
 then a selected sub-formula is distinguished either by displaying the
 non-selected portion of the formula with @code{calc-nonselected-face}
 or by displaying the selected sub-formula with

doc/misc/cc-mode.texi

@@ -2191,10 +2191,10 @@ foo& bar
 
 @defvar c-asymmetry-fontification-flag
 @vindex asymmetry-fontification-flag @r{(c-)}
-When @code{c-asymmetry-fontification-flag} is non-@code{nil} (which it is by
+When @code{c-asymmetry-fontification-flag} is non-@code{nil} (which it
-default), code like the above, with white space either before or after
+is by default), code like the above, with white space either before or
-the operator, but not both, is fontified as a declaration.  When the
+after the operator, but not both, is fontified as a declaration.  When
-variable is nil, such a construct gets the default face.
+the variable is @code{nil}, such a construct gets the default face.
 @end defvar
 
 When the construct is an expression there will often be white space
@@ -5998,7 +5998,7 @@ three syntactic symbols, @code{arglist-cont-nonempty},
 List Symbols}).
 
 This function is intended for use in a list.  If the construct being
-analyzed isn't like the preceding, the function returns nil.
+analyzed isn't like the preceding, the function returns @code{nil}.
 Otherwise it returns the function
 @code{c-lineup-arglist-intro-after-paren}, which the caller then uses
 to perform indentation.
@@ -6042,8 +6042,8 @@ also has a syntactic element with the symbol @code{brace-list-entry}
 (@pxref{Brace List Symbols}).
 
 This function is intended for use in a list.  If the above structure
-isn't present, the function returns nil, allowing a different offset
+isn't present, the function returns @code{nil}, allowing a different
-specification to indent the line.
+offset specification to indent the line.
 
 @workswith{} @code{brace-list-intro}.
 @end defun
@@ -6085,8 +6085,8 @@ returning the symbol @code{c-lineup-arglist-intro-after-paren}, which
 the caller then uses to perform the indentation.
 
 This function is intended for use in a list.  If the above structure
-isn't present, the function returns nil, allowing a different offset
+isn't present, the function returns @code{nil}, allowing a different
-specification to indent the line.
+offset specification to indent the line.
 
 @workswith{} @code{brace-list-intro}.
 @end defun

doc/misc/ede.texi

@@ -1896,19 +1896,19 @@ Make sure the @code{:file} is fully expanded.
 @end deffn
 
 @deffn Method ede-preprocessor-map :AFTER this
-Get the pre-processor map for project @var{THIS}.
+Get the pre-processor map for project @var{this}.
 @end deffn
 
 @deffn Method ede-cpp-root-header-file-p :AFTER proj name
-Non @code{nil} if in @var{PROJ} the filename @var{NAME} is a header.
+Non-@code{nil} if in @var{proj} the filename @var{name} is a header.
 @end deffn
 
 @deffn Method ede-system-include-path :AFTER this
-Get the system include path used by project @var{THIS}.
+Get the system include path used by project @var{this}.
 @end deffn
 
 @deffn Method ede-expand-filename-impl :AFTER proj name
-Within this project @var{PROJ}, find the file @var{NAME}.
+Within this project @var{proj}, find the file @var{name}.
 This knows details about or source tree.
 @end deffn
 
@@ -2796,7 +2796,7 @@ File name of generated Makefile.
 Type: @code{boolean} @*
 Default Value: @code{t}
 
-Non @code{nil} means the rule created is part of the all target.
+Non-@code{nil} means the rule created is part of the all target.
 Setting this to @code{nil} creates the rule to build this item, but does not
 include it in the @code{all:} rule.
 
@@ -3888,10 +3888,10 @@ themselves.
 Type: @code{boolean} @*
 Default Value: @code{nil}
 
-Non @code{nil} if this sourcecode type uses subdirectores.
+Non-@code{nil} if this sourcecode type uses subdirectores.  If
-If sourcecode always lives near the target creating it, this should be nil.
+sourcecode always lives near the target creating it, this should be
-If sourcecode can, or typically lives in a subdirectory of the owning
+@code{nil}.  If sourcecode can, or typically lives in a subdirectory
-target, set this to t.
+of the owning target, set this to @code{t}.
 
 @item :garbagepattern
 Type: @code{list} @*

doc/misc/ert.texi

@@ -409,13 +409,13 @@ emacs -batch -l ert -l my-tests.el \
 @end example
 
 @vindex ert-batch-backtrace-line-length
-Even modest settings for @code{print-level} and @code{print-length} can
+Even modest settings for @code{print-level} and @code{print-length}
-produce extremely long lines in backtraces, however, with attendant
+can produce extremely long lines in backtraces, however, with
-pauses in execution progress.  Set
+attendant pauses in execution progress.  Set
-@code{ert-batch-backtrace-line-length} to t to use the value of
+@code{ert-batch-backtrace-line-length} to @code{t} to use the value of
-@code{backtrace-line-length}, @code{nil} to stop any limitations on backtrace
+@code{backtrace-line-length}, @code{nil} to stop any limitations on
-line lengths (that is, to get full backtraces), or a positive integer to
+backtrace line lengths (that is, to get full backtraces), or a
-limit backtrace line length to that number.
+positive integer to limit backtrace line length to that number.
 
 @vindex ert-quiet
 By default, ERT in batch mode is quite verbose, printing a line with

doc/misc/eudc.texi

@@ -374,7 +374,7 @@ LDAP:
 Specifying the function @code{ldap-password-read} for @code{passwd}
 will cause Emacs to prompt interactively for the password.  The
 password will then be validated and cached, unless
-@code{password-cache} is nil.  You can customize
+@code{password-cache} is @code{nil}.  You can customize
 @code{password-cache-expiry} to control the duration for which the
 password is cached.  If you want to clear the cache, call
 @code{password-reset}.
@@ -1023,9 +1023,9 @@ current server to the list with the command @kbd{M-x
 eudc-bookmark-current-server}.  The list is contained in the variable
 @code{eudc-server-hotlist} which is stored in and retrieved from the
 file designated by @code{eudc-options-file}, or normal Emacs
-initialization if @code{eudc-ignore-options-file} is non-nil.  EUDC
+initialization if @code{eudc-ignore-options-file} is non-@code{nil}.
-also provides a facility to edit the hotlist interactively (@pxref{The
+EUDC also provides a facility to edit the hotlist interactively
-Hotlist Edit Buffer}).
+(@pxref{The Hotlist Edit Buffer}).
 
 The hotlist is also used to make queries on multiple servers
 successively (@pxref{Multi-server Queries}).  The order in which the
@@ -1041,18 +1041,18 @@ Add the current server to the hotlist of servers
 @end deffn
 
 @defvar eudc-ignore-options-file
-If non-nil, then EUDC ignores @code{eudc-options-file} and warns or
+If non-@code{nil}, EUDC ignores @code{eudc-options-file} and warns or
 issues an error when an attempt is made to use it.  Most users should
 set this, and keep their EUDC configuration in the main Emacs
-initialization file instead.  The separate eudc-options file has
+initialization file instead.  The separate @file{eudc-options} file
-created confusion for users in the past.
+has created confusion for users in the past.
 @end defvar
 
 @defvar eudc-options-file
 The name of a file where EUDC stores its internal variables (the
 hotlist and the current server).  EUDC will try to load that file upon
 initialization so, if you choose a file name different from the
-defaults @file{~/.emacs.d/eudc-options}, be sure to set this variable
+default @file{~/.emacs.d/eudc-options}, be sure to set this variable
 to the appropriate value @emph{before} EUDC is itself loaded.
 @end defvar
 

doc/misc/eww.texi

@@ -367,8 +367,8 @@ point positions or the actual Web page contents.
 The latter, however, tend to be overly large to preserve in the
 desktop file, so they get omitted, thus rendering the respective
 entries entirely equivalent.  By default, such duplicate entries are
-not saved.  Setting @code{eww-desktop-remove-duplicates} to nil will
+not saved.  Setting @code{eww-desktop-remove-duplicates} to @code{nil}
-force EWW to save them anyway.
+will force EWW to save them anyway.
 
 @vindex eww-restore-desktop
   Restoring EWW buffers' contents may prove to take too long to

doc/misc/flymake.texi

@@ -115,11 +115,11 @@ Syntax checks happen ``on-the-fly''.  Each check is started whenever:
 @itemize @bullet
 @item
 @code{flymake-mode} is started, unless
-@code{flymake-start-on-flymake-mode} is nil;
+@code{flymake-start-on-flymake-mode} is @code{nil};
 
 @item
 the buffer is saved, unless @code{flymake-start-on-save-buffer} is
-nil;
+@code{nil};
 
 @item
 some changes were made to the buffer more than @code{0.5} seconds ago
@@ -876,13 +876,18 @@ Patterns for error/warning messages in the form @code{(regexp file-idx
 line-idx col-idx err-text-idx)}.  @xref{Parsing the output}.
 
 @item flymake-proc-diagnostic-type-pred
-A function to classify a diagnostic text as particular type of error.
+A function to classify a diagnostic text as a particular type of
-Should be a function taking an error text and returning a diagnostic
+error.  The value of this variable should be a function taking an
-symbol (@pxref{Flymake error types}).  If non-@code{nil} is returned but
+error text and returning a diagnostic symbol (@pxref{Flymake error
-there is no such symbol in that table, a warning is assumed.  If nil
+types}).  If it returns a non-@code{nil} value but there is no such
-is returned, an error is assumed.  Can also be a regular expression
+symbol in that table, the text is interpreted as a warning.  If the
-that should match only warnings.  This variable replaces the old
+function returns @code{nil}, the text is assumed to be an error.
-@code{flymake-warning-re} and @code{flymake-warning-predicate}.
+
+The value of this variable can alternatively be a regular expression
+that should match only warnings.
+
+This variable replaces the old @code{flymake-warning-re} and
+@code{flymake-warning-predicate}.
 
 @item flymake-proc-compilation-prevents-syntax-check
 A flag indicating whether compilation and syntax check of the same

doc/misc/gnus.texi

@@ -5014,14 +5014,14 @@ the @code{a} spec.
 @item L
 Number of lines in the article.
 @item Z
-Retrieval Score Value (RSV) of the article; nil if not in an nnselect
+Retrieval Score Value (RSV) of the article; @code{nil} if not in an
-group.
+nnselect group.
 @item G
-Originating group name of the article; nil if not in an nnselect
+Originating group name of the article; @code{nil} if not in an
-group.
+nnselect group.
 @item g
-Short form of the originating group name of the article; nil if not in
+Short form of the originating group name of the article; @code{nil} if
-an nnselect group.
+not in an nnselect group.
 @item c
 Number of characters in the article.  This specifier is not supported
 in some methods (like nnfolder).
@@ -14568,18 +14568,20 @@ requires using the @file{oauth2.el} library.)
 @vindex nnimap-expunge
 @item nnimap-expunge
 When to expunge deleted messages.  If @code{never}, deleted articles
-are marked with the IMAP @code{\\Delete} flag but not automatically
+are marked with the @acronym{IMAP} @code{\\Delete} flag but not
-expunged. If @code{immediately}, deleted articles are immediately expunged
+automatically expunged.  If @code{immediately}, deleted articles are
-(this requires the server to support the UID EXPUNGE command). If
+immediately expunged (this requires the server to support the
-@code{on-exit}, deleted articles are flagged, and all flagged articles are
+@code{UID EXPUNGE} command).  If @code{on-exit}, deleted articles are
-expunged when the group is closed.
+flagged, and all flagged articles are expunged when the group is
+closed.
 
-For backwards compatibility, this variable may also be set to t
+For backwards compatibility, this variable may also be set to @code{t}
-or nil. If the server supports UID EXPUNGE, both t and nil are
+or @code{nil}.  If the server supports @code{UID EXPUNGE}, both
-equivalent to @code{immediately}. If the server does not support UID
+@code{t} and @code{nil} are equivalent to @code{immediately}.  If the
-EXPUNGE nil is equivalent to @code{never}, while t will immediately
+server does not support @code{UID EXPUNGE}, @code{nil} is equivalent
-expunge ALL articles that are currently flagged as deleted
+to @code{never}, while @code{t} will immediately expunge @emph{all}
-(i.e., potentially not only the article that was just deleted).
+articles that are currently flagged as deleted (i.e., potentially not
+only the article that was just deleted).
 
 @vindex nnimap-streaming
 @item nnimap-streaming
@@ -15296,9 +15298,9 @@ Two example maildir mail sources:
 @end lisp
 
 @item imap
-Get mail from a @acronym{IMAP} server.  If you don't want to use
+Get mail from an @acronym{IMAP} server.  If you don't want to use
 @acronym{IMAP} as intended, as a network mail reading protocol (i.e.,
-with nnimap), for some reason or other, Gnus let you treat it similar
+with nnimap), for some reason or other, Gnus lets you treat it similar
 to a @acronym{POP} server and fetches articles from a given
 @acronym{IMAP} mailbox.  @xref{Using IMAP}, for more information.
 
@@ -19404,7 +19406,7 @@ If you so desire, you can configure the agent (see @code{gnus-agent-cache}
 @pxref{Agent Variables}) to always download headers and articles while
 plugged.  Gnus will almost certainly be slower, but it will be kept
 synchronized with the server.  That last point probably won't make any
-sense if you are using a nntp or nnimap back end.
+sense if you are using an nntp or nnimap back end.
 
 @node Agent Expiry
 @subsection Agent Expiry
@@ -26369,7 +26371,7 @@ If this option is non-@code{nil}, the registry will register all messages, as
 you see them.  This is important to making split-to-parent and
 Message-ID references work correctly, as the registry needs to know
 where all messages are, but it can slow down group opening and the
-saving of Gnus.  If this option is nil, entries must be created
+saving of Gnus.  If this option is @code{nil}, entries must be created
 manually, for instance by storing a custom flag or keyword for the
 message.
 @end defvar
@@ -26391,8 +26393,8 @@ This option specifies how registry entries are sorted during pruning.
 If a function is given, it should sort least valuable entries first,
 as pruning starts from the beginning of the list.  The default value
 is @code{gnus-registry-sort-by-creation-time}, which proposes the
-oldest entries for pruning.  Set to nil to perform no sorting, which
+oldest entries for pruning.  Set to @code{nil} to perform no sorting,
-will speed up the pruning process.
+which will speed up the pruning process.
 @end defvar
 
 @defvar gnus-registry-cache-file
@@ -26465,10 +26467,10 @@ have to put a rule like this:
 
 in your fancy split setup.
 
-If @code{gnus-registry-register-all} is non-@code{nil} (the default), the
+If @code{gnus-registry-register-all} is non-@code{nil} (the default),
-registry will perform splitting for all messages.  If it is nil,
+the registry will perform splitting for all messages.  If it is
-splitting will only happen for children of messages you've explicitly
+@code{nil}, splitting will only happen for children of messages you've
-registered.
+explicitly registered.
 
 In addition, you may want to customize the following variables.
 

doc/misc/tramp.texi

@@ -3553,7 +3553,7 @@ completion lists.  If you want to suppress this completion because
 there are invalid entries in the persistency file, for example if the
 host configuration changes often, or if you plug your laptop to
 different networks frequently, you can set the user option
-@code{tramp-completion-use-cache} to nil.
+@code{tramp-completion-use-cache} to @code{nil}.
 
 After remote host name completion comes completion of file names on
 the remote host.  It works the same as with local host file completion