Don't quote nil and t in doc strings

This is as per "Tips for Documentation Strings" in the elisp manual.
For consistency, do the same in diagnostics and comments.

97 files changed, 177 insertions, 177 deletions

diff --git a/lisp/allout-widgets.el b/lisp/allout-widgets.el
index 164cd3192ac..3c71a810bfb 100644
--- a/lisp/allout-widgets.el
+++ b/lisp/allout-widgets.el
@@ -348,7 +348,7 @@ to `allout-body-modification-handler', and is always reset by
 images with lists containing the name of the icon directory (as
 found on the `load-path') and the icon name.
 
-Set this variable to `nil' to empty the cache, and have it replenish from the
+Set this variable to nil to empty the cache, and have it replenish from the
 filesystem.")
 ;;;_    = allout-widgets-unset-inhibit-read-only
 (defvar allout-widgets-unset-inhibit-read-only nil
diff --git a/lisp/allout.el b/lisp/allout.el
index 2cdac99f90a..dcdd35eb488 100644
--- a/lisp/allout.el
+++ b/lisp/allout.el
@@ -322,7 +322,7 @@ With value nil, inhibit any automatic allout-mode activation."
   "Default allout outline layout specification.
 
 This setting specifies the outline exposure to use when
-`allout-layout' has the local value `t'.  This docstring describes the
+`allout-layout' has the local value t.  This docstring describes the
 layout specifications.
 
 A list value specifies a default layout for the current buffer,
@@ -933,7 +933,7 @@ followed by the equivalent of `(allout-expose-topic 0 : -1 -1 0)'.
 \(This is the layout used for the allout.el source file.)
 
 `allout-default-layout' describes the specification format.
-`allout-layout' can additionally have the value `t', in which
+`allout-layout' can additionally have the value t, in which
 case the value of `allout-default-layout' is used.")
 (make-variable-buffer-local 'allout-layout)
 ;;;###autoload
diff --git a/lisp/calc/calc-yank.el b/lisp/calc/calc-yank.el
index 726a7202a8a..923df5d577f 100644
--- a/lisp/calc/calc-yank.el
+++ b/lisp/calc/calc-yank.el
@@ -149,7 +149,7 @@ as well as set the contents of the Emacs register REGISTER to TEXT."
   "Return the CALCVAL portion of the contents of the Calc register REG,
 unless the TEXT portion doesn't match the contents of the Emacs register REG,
 in which case either return the contents of the Emacs register (if it is
-text) or `nil'."
+text) or nil."
   (let ((cval (cdr (assq reg calc-register-alist)))
         (val (cdr (assq reg register-alist))))
     (if (stringp val)
diff --git a/lisp/calc/calc.el b/lisp/calc/calc.el
index 1cc11b48ac3..52ed5d7eb3d 100644
--- a/lisp/calc/calc.el
+++ b/lisp/calc/calc.el
@@ -2034,7 +2034,7 @@ See calc-keypad for details."
 ;; (YEAR MONTH DAY math-date-from-gregorian-dt(YEAR MONTH DAY)) for speed.
 (defcustom calc-gregorian-switch nil
   "The first day the Gregorian calendar is used by Calc's date forms.
-This is `nil' (the default) if the Gregorian calendar is the only one used.
+This is nil (the default) if the Gregorian calendar is the only one used.
 Otherwise, it should be a list `(YEAR MONTH DAY)' when Calc begins to use
 the Gregorian calendar; Calc will use the Julian calendar for earlier dates.
 The dates in which different regions of the world began to use the
diff --git a/lisp/calendar/diary-lib.el b/lisp/calendar/diary-lib.el
index 29364b55b6c..d5bd26a9277 100644
--- a/lisp/calendar/diary-lib.el
+++ b/lisp/calendar/diary-lib.el
@@ -104,9 +104,9 @@ are: `string', `symbol', `int', `tnil', `stringtnil.'"
                        (choice (const string :tag "A string")
                                (const symbol :tag "A symbol")
                                (const int :tag "An integer")
-                               (const tnil :tag "`t' or `nil'")
+                               (const tnil :tag "t or nil")
                                (const stringtnil
-                                      :tag "A string, `t', or `nil'"))))
+                                      :tag "A string, t, or nil"))))
   :group 'diary)
 
 (defcustom diary-glob-file-regexp-prefix "^\\#"
@@ -1671,7 +1671,7 @@ DAY MONTH YEAR in the European style).
 
   %%(diary-date MONTH DAY YEAR &optional MARK) text
     Entry applies if date is MONTH, DAY, YEAR.  DAY, MONTH, and YEAR can
-    be a list of integers, `t' (meaning all values), or an integer.
+    be a list of integers, t (meaning all values), or an integer.
 
   %%(diary-float MONTH DAYNAME N &optional DAY MARK) text
     Entry will appear on the Nth DAYNAME after/before MONTH DAY.
@@ -1679,7 +1679,7 @@ DAY MONTH YEAR in the European style).
     If N>0, use the Nth DAYNAME after MONTH DAY.
     If N<0, use the Nth DAYNAME before MONTH DAY.
     DAY defaults to 1 if N>0, and MONTH's last day otherwise.
-    MONTH can be a list of months, a single month, or `t' to
+    MONTH can be a list of months, a single month, or t to
     specify all months.
 
   %%(diary-block M1 D1 Y1 M2 D2 Y2 &optional MARK) text
@@ -1814,7 +1814,7 @@ form used internally by the calendar and diary."
 (defun diary-date (month day year &optional mark)
   "Specific date(s) diary entry.
 Entry applies if date is MONTH, DAY, YEAR.  Each parameter can be a
-list of integers, `t' (meaning all values), or an integer.  The order
+list of integers, t (meaning all values), or an integer.  The order
 of the input parameters changes according to `calendar-date-style'
 \(e.g. to DAY MONTH YEAR in the European style).
 
@@ -1863,7 +1863,7 @@ DAYNAME=0 means Sunday, DAYNAME=1 means Monday, and so on.
 If N>0, use the Nth DAYNAME after MONTH DAY.
 If N<0, use the Nth DAYNAME before MONTH DAY.
 DAY defaults to 1 if N>0, and MONTH's last day otherwise.
-MONTH can be a list of months, an integer, or `t' (meaning all months).
+MONTH can be a list of months, an integer, or t (meaning all months).
 Optional MARK specifies a face or single-character string to use when
 highlighting the day in the calendar."
   ;; This is messy because the diary entry may apply, but the date on which it
diff --git a/lisp/calendar/todo-mode.el b/lisp/calendar/todo-mode.el
index bb9316c81d7..7369ec28c29 100644
--- a/lisp/calendar/todo-mode.el
+++ b/lisp/calendar/todo-mode.el
@@ -5443,7 +5443,7 @@ dynamically create item insertion commands.")
 The list consists of item insertion parameters that can be passed
 as insertion command arguments in fixed positions.  If a position
 in the list is not occupied by the corresponding parameter, it is
-occupied by `nil'."
+occupied by nil."
   (let* ((arg (list (car todo-insert-item--args)))
          (args (nconc (cdr todo-insert-item--args)
                       (list (car (todo-insert-item--argsleft
diff --git a/lisp/cedet/ede/auto.el b/lisp/cedet/ede/auto.el
index 7e8df6b89af..482632f294a 100644
--- a/lisp/cedet/ede/auto.el
+++ b/lisp/cedet/ede/auto.el
@@ -86,7 +86,7 @@ into memory.")
      ;; If the thing to match is stored in a config file.
      ((stringp fc)
       (when (file-exists-p fc)
-        (let ((matchstring 
+        (let ((matchstring
                (if (slot-boundp dirmatch 'configdatastash)
                    (oref dirmatch configdatastash)
                  nil)))
@@ -123,7 +123,7 @@ into memory.")
                    (not (= (match-end 0) (length file))))
                )
           )))
-     
+
      ;; Add new matches here
      ;; ((stringp somenewslot ...)
      ;;   )
@@ -155,9 +155,9 @@ into memory.")
 Specifying this matcher object will allow EDE to perform a complex
 check without loading the project.
 
-NOTE: If you use dirmatch, you may need to set :root-only to `nil'.
+NOTE: If you use dirmatch, you may need to set :root-only to nil.
 While it may be a root based project, all subdirs will happen to return
-true for the dirmatch, so for scanning purposes, set it to `nil'.") 
+true for the dirmatch, so for scanning purposes, set it to nil.")
    (proj-root :initarg :proj-root
               :type function
               :documentation "A function symbol to call for the project root.
@@ -280,7 +280,7 @@ added.  Possible values are:
     (if f
         (and f (file-exists-p f))
       (let ((dirmatch (oref this proj-root-dirmatch)))
-        (cond 
+        (cond
          ((stringp dirmatch)
           nil) ; <- do something here - maybe obsolete the option?
          ((ede-project-autoload-dirmatch-p dirmatch)
@@ -312,7 +312,7 @@ NOTE: Do not call this - it should only be called from `ede-load-project-file'."
 
 
 
-;;; -------- Old Methods 
+;;; -------- Old Methods
 ;; See if we can do without them.
 
 ;; @FIXME - delete from loaddefs to remove this.
diff --git a/lisp/cedet/ede/files.el b/lisp/cedet/ede/files.el
index 1922337feb0..4ba823adeee 100644
--- a/lisp/cedet/ede/files.el
+++ b/lisp/cedet/ede/files.el
@@ -41,7 +41,7 @@
 (declare-function ede-locate-flush-hash "ede/locate")
 
 (defvar ede--disable-inode nil
-  "Set to 't' to simulate systems w/out inode support.")
+  "Set to t to simulate systems w/out inode support.")
 
 ;;; Code:
 ;;;###autoload
diff --git a/lisp/cus-edit.el b/lisp/cus-edit.el
index 9f57d0da24a..1d9a9d6d426 100644
--- a/lisp/cus-edit.el
+++ b/lisp/cus-edit.el
@@ -1965,7 +1965,7 @@ Each entry is of the form (STATE MAGIC FACE ITEM-DESC [ GROUP-DESC ]), where
 
 STATE is one of the following symbols:
 
-`nil'
+nil
    For internal use, should never occur.
 `unknown'
    For internal use, should never occur.
diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 4dcb519b039..18a3c887aad 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -2257,7 +2257,7 @@ of marked files.  If KILL-ROOT is non-nil, kill DIRNAME as well."
   ;;   components are string-lessp.
   ;; Thus ("/usr/" "/usr/bin") and ("/usr/a/" "/usr/b/") are tree-lessp.
   ;; string-lessp could arguably be replaced by file-newer-than-file-p
-  ;;   if dired-actual-switches contained `t'.
+  ;;   if dired-actual-switches contained t.
   (setq dir1 (file-name-as-directory dir1)
         dir2 (file-name-as-directory dir2))
   (let ((components-1 (dired-split "/" dir1))
diff --git a/lisp/dired.el b/lisp/dired.el
index ca13900f681..e523b941295 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -3889,7 +3889,7 @@ Ask means pop up a menu for the user to select one of copy, move or link."
 
 ;;; Start of automatically extracted autoloads.
 
-;;;### (autoloads nil "dired-aux" "dired-aux.el" "8820677763cb69eef827e38b86d35f47")
+;;;### (autoloads nil "dired-aux" "dired-aux.el" "45867cb96abef86d29a9850ee2113cf2")
 ;;; Generated autoloads from dired-aux.el
 
 (autoload 'dired-diff "dired-aux" "\
diff --git a/lisp/dirtrack.el b/lisp/dirtrack.el
index d1957a259b1..d1c46dd8550 100644
--- a/lisp/dirtrack.el
+++ b/lisp/dirtrack.el
@@ -51,7 +51,7 @@
 ;; which matches your prompt up to and including the pathname part.
 ;; The second is a number which tells which regular expression group to
 ;; match to extract only the pathname.  If you use a multi-line prompt,
-;; add 't' as a third element.  Note that some of the functions in
+;; add t as a third element.  Note that some of the functions in
 ;; 'comint.el' assume a single-line prompt (eg, comint-bol).
 ;;
 ;; Determining this information may take some experimentation.  Using
diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 67744c69b14..efd43898b60 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -348,7 +348,7 @@ else the global value will be modified."
 ;;;###autoload
 (defun byte-compile-enable-warning (warning)
   "Change `byte-compile-warnings' to enable WARNING.
-If `byte-compile-warnings' is `t', do nothing.  Otherwise, if the
+If `byte-compile-warnings' is t, do nothing.  Otherwise, if the
 first element is `not', remove WARNING, else add it.
 Normally you should let-bind `byte-compile-warnings' before calling this,
 else the global value will be modified."
diff --git a/lisp/emacs-lisp/check-declare.el b/lisp/emacs-lisp/check-declare.el
index 7269b83b619..ecdb6d8983c 100644
--- a/lisp/emacs-lisp/check-declare.el
+++ b/lisp/emacs-lisp/check-declare.el
@@ -98,7 +98,7 @@ don't know how to recognize (e.g. some macros)."
                  (stringp (setq fnfile (nth 2 form)))
                  (setq fnfile (check-declare-locate fnfile
                                                     (expand-file-name file)))
-                 ;; Use `t' to distinguish unspecified arglist from empty one.
+                 ;; Use t to distinguish unspecified arglist from empty one.
                  (or (eq t (setq arglist (if (> len 3)
                                              (nth 3 form)
                                            t)))
diff --git a/lisp/emacs-lisp/checkdoc.el b/lisp/emacs-lisp/checkdoc.el
index fc257d0d520..18361c8888f 100644
--- a/lisp/emacs-lisp/checkdoc.el
+++ b/lisp/emacs-lisp/checkdoc.el
@@ -1615,8 +1615,8 @@ function,command,variable,option or symbol." ms1))))))
             (or
              ;; * The documentation string for a variable that is a
              ;;   yes-or-no flag should start with words such as Non-nil
-             ;;   means..., to make it clear that all non-`nil' values are
-             ;;   equivalent and indicate explicitly what `nil' and non-`nil'
+             ;;   means..., to make it clear that all non-nil values are
+             ;;   equivalent and indicate explicitly what nil and non-nil
              ;;   mean.
              ;; * If a user option variable records a true-or-false
              ;;   condition, give it a name that ends in `-flag'.
diff --git a/lisp/emacs-lisp/cl-generic.el b/lisp/emacs-lisp/cl-generic.el
index a2716ef87ee..13585bcaf18 100644
--- a/lisp/emacs-lisp/cl-generic.el
+++ b/lisp/emacs-lisp/cl-generic.el
@@ -525,7 +525,7 @@ which case this method will be invoked when the argument is `eql' to VAL.
           (progn
             (while (and dispatches
                         (let ((x (nth 1 (car dispatches))))
-                          ;; No need to dispatch for `t' specializers.
+                          ;; No need to dispatch for t specializers.
                           (or (null x) (equal x cl--generic-t-generalizer))))
               (setq dispatches (cdr dispatches)))
             (pop dispatches))))
@@ -701,7 +701,7 @@ methods.")
       #'cl--generic-standard-method-combination)
 
 (cl-defmethod cl-generic-generalizers (specializer)
-  "Support for the catch-all `t' specializer."
+  "Support for the catch-all t specializer."
   (if (eq specializer t) (list cl--generic-t-generalizer)
     (error "Unknown specializer %S" specializer)))
 
diff --git a/lisp/emacs-lisp/cl-indent.el b/lisp/emacs-lisp/cl-indent.el
index 5e75406cf22..57da7159d5c 100644
--- a/lisp/emacs-lisp/cl-indent.el
+++ b/lisp/emacs-lisp/cl-indent.el
@@ -140,13 +140,13 @@ If non-nil, alignment is done with the first parameter
 
 (defcustom lisp-indent-backquote-substitution-mode t
   "How to indent substitutions in backquotes.
-If `t', the default, indent substituted forms normally.
-If `nil', do not apply special indentation rule to substituted
+If t, the default, indent substituted forms normally.
+If nil, do not apply special indentation rule to substituted
 forms.  If `corrected', subtract the `,' or `,@' from the form
 column, indenting as if this character sequence were not present.
 In any case, do not backtrack beyond a backquote substitution.
 
-Until Emacs 25.1, the `nil' behavior was hard-wired."
+Until Emacs 25.1, the nil behavior was hard-wired."
   :version "25.1"
   :type '(choice (const corrected) (const nil) (const t))
   :group 'lisp-indent)
diff --git a/lisp/emacs-lisp/debug.el b/lisp/emacs-lisp/debug.el
index 9d32ba241de..77d6332feee 100644
--- a/lisp/emacs-lisp/debug.el
+++ b/lisp/emacs-lisp/debug.el
@@ -54,7 +54,7 @@ the middle is discarded, and just the beginning and end are displayed."
 The value affects the behavior of operations on any window
 previously showing the debugger buffer.
 
-`nil' means that if its window is not deleted when exiting the
+nil means that if its window is not deleted when exiting the
   debugger, invoking `switch-to-prev-buffer' will usually show
   the debugger buffer again.
 
diff --git a/lisp/emacs-lisp/edebug.el b/lisp/emacs-lisp/edebug.el
index 98fb7e9888c..b5da3cc2174 100644
--- a/lisp/emacs-lisp/edebug.el
+++ b/lisp/emacs-lisp/edebug.el
@@ -600,7 +600,7 @@ list of a symbol.")
 (defun edebug-get-form-data-entry (pnt &optional end-point)
   ;; Find the edebug form data entry which is closest to PNT.
   ;; If END-POINT is supplied, match must be exact.
-  ;; Return `nil' if none found.
+  ;; Return nil if none found.
   (let ((rest edebug-form-data)
         closest-entry
         (closest-dist 999999))  ;; Need maxint here.
diff --git a/lisp/emacs-lisp/syntax.el b/lisp/emacs-lisp/syntax.el
index 81ef7a6fbf3..05dd7d57503 100644
--- a/lisp/emacs-lisp/syntax.el
+++ b/lisp/emacs-lisp/syntax.el
@@ -574,7 +574,7 @@ running the hook."
 
 ;; (defun buffer-syntactic-context (&optional buffer)
 ;;   "Syntactic context at point in BUFFER.
-;; Either of `string', `comment' or `nil'.
+;; Either of `string', `comment' or nil.
 ;; This is an XEmacs compatibility function."
 ;;   (with-current-buffer (or buffer (current-buffer))
 ;;     (syntax-ppss-context (syntax-ppss))))
diff --git a/lisp/emulation/viper-util.el b/lisp/emulation/viper-util.el
index 59f47525e55..c4dc569efb3 100644
--- a/lisp/emulation/viper-util.el
+++ b/lisp/emulation/viper-util.el
@@ -1301,7 +1301,7 @@ Usually contains ` ', linefeed, TAB or formfeed.")
     ))
 
 ;; SYMBOL is used because customize requires it, but it is ignored, unless it
-;; is `nil'.  If nil, use setq.
+;; is nil.  If nil, use setq.
 (defun viper-set-syntax-preference (&optional symbol value)
   "Set Viper syntax preference.
 If called interactively or if SYMBOL is nil, sets syntax preference in current
diff --git a/lisp/erc/erc-ezbounce.el b/lisp/erc/erc-ezbounce.el
index 5f91be8c899..de2a2ff6e76 100644
--- a/lisp/erc/erc-ezbounce.el
+++ b/lisp/erc/erc-ezbounce.el
@@ -78,7 +78,7 @@ The alist's format is as follows:
 (defun erc-ezb-get-login (server port)
   "Return an appropriate EZBounce login for SERVER and PORT.
 Look up entries in `erc-ezb-login-alist'. If the username or password
-in the alist is `nil', prompt for the appropriate values."
+in the alist is nil, prompt for the appropriate values."
   (let ((login (cdr (assoc (cons server port) erc-ezb-login-alist))))
     (when login
       (let ((username (car login))
diff --git a/lisp/erc/erc-pcomplete.el b/lisp/erc/erc-pcomplete.el
index 7f901edfb8f..e46ac68b259 100644
--- a/lisp/erc/erc-pcomplete.el
+++ b/lisp/erc/erc-pcomplete.el
@@ -33,7 +33,7 @@
 ;;
 ;; If you want nickname completions ordered such that the most recent
 ;; speakers are listed first, set
-;; `erc-pcomplete-order-nickname-completions' to `t'.
+;; `erc-pcomplete-order-nickname-completions' to t.
 ;;
 ;; See CREDITS for other contributors.
 ;;
diff --git a/lisp/eshell/esh-mode.el b/lisp/eshell/esh-mode.el
index 222e801301b..0dac4780690 100644
--- a/lisp/eshell/esh-mode.el
+++ b/lisp/eshell/esh-mode.el
@@ -206,7 +206,7 @@ This is used by `eshell-watch-for-password-prompt'."
 
 ;; Internal Variables:
 
-;; these are only set to `nil' initially for the sake of the
+;; these are only set to nil initially for the sake of the
 ;; byte-compiler, when compiling other files which `require' this one
 (defvar eshell-mode nil)
 (defvar eshell-mode-map nil)
diff --git a/lisp/eshell/esh-util.el b/lisp/eshell/esh-util.el
index 697f97e0460..170779fc5cd 100644
--- a/lisp/eshell/esh-util.el
+++ b/lisp/eshell/esh-util.el
@@ -33,7 +33,7 @@
 ;;; User Variables:
 
 (defcustom eshell-stringify-t t
-  "If non-nil, the string representation of t is 't'.
+  "If non-nil, the string representation of t is \"t\".
 If nil, t will be represented only in the exit code of the function,
 and not printed as a string.  This causes Lisp functions to behave
 similarly to external commands, as far as successful result output."
diff --git a/lisp/face-remap.el b/lisp/face-remap.el
index 3ec074b5599..93eec5bd13c 100644
--- a/lisp/face-remap.el
+++ b/lisp/face-remap.el
@@ -187,7 +187,7 @@ of face attribute/value pairs, like in a `face' text property.
 
 If SPECS is empty, call `face-remap-reset-base' to use the normal
 definition of FACE as the base remapping; note that this is
-different from SPECS containing a single value `nil', which means
+different from SPECS containing a single value nil, which means
 not to inherit from the global definition of FACE at all."
   (while (and (consp specs) (not (null (car specs))) (null (cdr specs)))
     (setq specs (car specs)))
diff --git a/lisp/facemenu.el b/lisp/facemenu.el
index 2c246b44d54..3d5894309df 100644
--- a/lisp/facemenu.el
+++ b/lisp/facemenu.el
@@ -458,7 +458,7 @@ These special properties include `invisible', `intangible' and `read-only'."
 
 (defcustom list-colors-sort nil
   "Color sort order for `list-colors-display'.
-`nil' means default implementation-dependent order (defined in `x-colors').
+nil means default implementation-dependent order (defined in `x-colors').
 `name' sorts by color name.
 `rgb' sorts by red, green, blue components.
 `(rgb-dist . COLOR)' sorts by the RGB distance to the specified color.
diff --git a/lisp/files.el b/lisp/files.el
index ef6ac7b8c92..d82ff5e865f 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -1092,14 +1092,14 @@ Tip: You can use this expansion of remote identifier components
 
 (defcustom remote-file-name-inhibit-cache 10
   "Whether to use the remote file-name cache for read access.
-When `nil', never expire cached values (caution)
-When `t', never use the cache (safe, but may be slow)
+When nil, never expire cached values (caution)
+When t, never use the cache (safe, but may be slow)
 A number means use cached values for that amount of seconds since caching.
 
 The attributes of remote files are cached for better performance.
 If they are changed outside of Emacs's control, the cached values
 become invalid, and must be reread.  If you are sure that nothing
-other than Emacs changes the files, you can set this variable to `nil'.
+other than Emacs changes the files, you can set this variable to nil.
 
 If a remote file is checked regularly, it might be a good idea to
 let-bind this variable to a value less than the interval between
diff --git a/lisp/gnus/deuglify.el b/lisp/gnus/deuglify.el
index df54f74e4ef..b2a725b5402 100644
--- a/lisp/gnus/deuglify.el
+++ b/lisp/gnus/deuglify.el
@@ -78,7 +78,7 @@
 ;; `gnus-outlook-deuglify-unwrap-stop-chars'.  Setting this to ".?!"
 ;; inhibits unwrapping if the cited line ends with a full stop,
 ;; question mark or exclamation mark.  Note that this variable
-;; defaults to `nil', triggering a few false positives but generally
+;; defaults to nil, triggering a few false positives but generally
 ;; giving you better results.
 ;;
 ;; Unwrapping works on every level of citation.  Thus you will be able
diff --git a/lisp/gnus/gnus-cus.el b/lisp/gnus/gnus-cus.el
index 9271322f4ab..93b7a1ba635 100644
--- a/lisp/gnus/gnus-cus.el
+++ b/lisp/gnus/gnus-cus.el
@@ -272,7 +272,7 @@ DOC is a documentation string for the parameter.")
                (repeat (list (string :format "%v" :tag "File name"))))
        "Which score files to use when using score to select articles to fetch.
 
-    `nil'
+    nil
          All articles will be scored to zero (0).
 
     `file'
diff --git a/lisp/gnus/gnus-sum.el b/lisp/gnus/gnus-sum.el
index 1d8ad8e6acb..37a707ebe64 100644
--- a/lisp/gnus/gnus-sum.el
+++ b/lisp/gnus/gnus-sum.el
@@ -4376,7 +4376,7 @@ Returns HEADER if it was entered in the DEPENDENCIES.  Returns nil otherwise."
      ;; The last case ignores an existing entry, except it adds any
      ;; additional Xrefs (in case the two articles came from different
      ;; servers.
-     ;; Also sets `header' to `nil' meaning that the `dependencies'
+     ;; Also sets `header' to nil meaning that the `dependencies'
      ;; table was *not* modified.
      (t
       (mail-header-set-xref
diff --git a/lisp/gnus/message.el b/lisp/gnus/message.el
index 8bb0a78a446..9e813e6dfd1 100644
--- a/lisp/gnus/message.el
+++ b/lisp/gnus/message.el
@@ -1123,7 +1123,7 @@ e.g. using `gnus-posting-styles':
 
 (defcustom message-cite-style nil
   "*The overall style to be used when yanking cited text.
-Value is either `nil' (no variable overrides) or a let-style list
+Value is either nil (no variable overrides) or a let-style list
 of pairs (VARIABLE VALUE) that will be bound in
 `message-yank-original' to do the quoting.
 
diff --git a/lisp/gnus/nndoc.el b/lisp/gnus/nndoc.el
index c62697b6939..70d803faf54 100644
--- a/lisp/gnus/nndoc.el
+++ b/lisp/gnus/nndoc.el
@@ -199,7 +199,7 @@ from the document.")
 ;; lines in the body.  For MIME dissections only, ARTICLE-INSERT [5] and
 ;; SUMMARY-INSERT [6] give headers to insert for full article or summary line
 ;; generation, respectively.  Other headers usually follow directly from the
-;; buffer.  Value `nil' means no insert.
+;; buffer.  Value nil means no insert.
 (defvoo nndoc-dissection-alist nil)
 (defvoo nndoc-prepare-body-function nil)
 (defvoo nndoc-generate-head-function nil)
diff --git a/lisp/gnus/nnmaildir.el b/lisp/gnus/nnmaildir.el
index 21fa5b37aa4..da3d5460c2b 100644
--- a/lisp/gnus/nnmaildir.el
+++ b/lisp/gnus/nnmaildir.el
@@ -84,13 +84,13 @@ Some of the FLAGS correspond to Gnus marks.")
 
 (defsubst nnmaildir--mark-to-flag (mark)
   "Find the Maildir flag that corresponds to MARK (an atom).
-Return a character, or `nil' if not found.
+Return a character, or nil if not found.
 See `nnmaildir-flag-mark-mapping'."
   (car (rassq mark nnmaildir-flag-mark-mapping)))
 
 (defsubst nnmaildir--flag-to-mark (flag)
   "Find the Gnus mark that corresponds to FLAG (a character).
-Return an atom, or `nil' if not found.
+Return an atom, or nil if not found.
 See `nnmaildir-flag-mark-mapping'."
   (cdr (assq flag nnmaildir-flag-mark-mapping)))
 
diff --git a/lisp/gnus/rfc2047.el b/lisp/gnus/rfc2047.el
index b2520b26af9..ea558d75a20 100644
--- a/lisp/gnus/rfc2047.el
+++ b/lisp/gnus/rfc2047.el
@@ -1136,7 +1136,7 @@ other than `\"' and `\\' in quoted strings."
           ;; `decode-coding-string' in Emacs offers a third optional
           ;; arg NOCOPY to avoid consing a new string if the decoding
           ;; is "trivial".  Unfortunately it currently doesn't
-          ;; consider anything else than a `nil' coding system
+          ;; consider anything else than a nil coding system
           ;; trivial.
           ;; `rfc2047-decode-string' is called multiple times for each
           ;; article during summary buffer generation, and we really
diff --git a/lisp/ibuffer.el b/lisp/ibuffer.el
index f15e150f5d4..c426976b29c 100644
--- a/lisp/ibuffer.el
+++ b/lisp/ibuffer.el
@@ -1908,9 +1908,9 @@ the buffer object itself and the current mark symbol."
                      ;; Kill the line if the buffer is dead
                      'kill)))
               ;; A given mapping function should return:
-              ;; `nil' if it chose not to affect the buffer
+              ;; nil if it chose not to affect the buffer
               ;; `kill' means the remove line from the buffer list
-              ;; `t' otherwise
+              ;; t otherwise
               (cl-incf ibuffer-map-lines-total)
               (cond ((null result)
                      (forward-line 1))
diff --git a/lisp/ielm.el b/lisp/ielm.el
index be877eb250a..3c9908ac362 100644
--- a/lisp/ielm.el
+++ b/lisp/ielm.el
@@ -511,7 +511,7 @@ evaluations respectively.  If the working buffer is another IELM
 buffer, then the values in the working buffer are used.  The variables
 `*1', `*2' and `*3', yield the process buffer values.
 
-If, at the start of evaluation, `standard-output' is `t' (the
+If, at the start of evaluation, `standard-output' is t (the
 default), `standard-output' is set to a special function that
 causes output to be directed to the ielm buffer.
 `standard-output' is restored after evaluation unless explicitly
diff --git a/lisp/info.el b/lisp/info.el
index 05574ae11f5..d63581911c5 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -303,7 +303,7 @@ when you hit the end of the current node."
   "If non-nil, hide the tag and section reference in *note and * menu items.
 If value is non-nil but not `hide', also replaces the \"*note\" with \"see\".
 If value is non-nil but not t or `hide', the reference section is still shown.
-`nil' completely disables this feature.  If this is non-nil, you might
+nil completely disables this feature.  If this is non-nil, you might
 want to set `Info-refill-paragraphs'."
   :version "22.1"
   :type '(choice (const :tag "No hiding" nil)
diff --git a/lisp/language/tv-util.el b/lisp/language/tv-util.el
index 400856d1aa3..ba1ee668825 100644
--- a/lisp/language/tv-util.el
+++ b/lisp/language/tv-util.el
@@ -34,7 +34,7 @@
                     (combining-vowel . "ꪴꪰꪲꪳꪷꪸꪾ")
                     (combining-tone . "꪿꫁")
                     (misc . "-"))))
-    ;; Set all TaiViet characters to `t'.
+    ;; Set all TaiViet characters to t.
     (set-char-table-range table (cons #xaa80 #xaac2) t)
     (set-char-table-range table (cons #xaadb #xaadf) t)
     ;; Overwrite it for special characters.
diff --git a/lisp/linum.el b/lisp/linum.el
index 2aac13ab9b0..7b6a3ea4e42 100644
--- a/lisp/linum.el
+++ b/lisp/linum.el
@@ -62,7 +62,7 @@ See also `linum-before-numbering-hook'."
 
 (defcustom linum-eager t
   "Whether line numbers should be updated after each command.
-The conservative setting `nil' might miss some buffer changes,
+The conservative setting nil might miss some buffer changes,
 and you have to scroll or press \\[recenter-top-bottom] to update the numbers."
   :group 'linum
   :type 'boolean)
diff --git a/lisp/ls-lisp.el b/lisp/ls-lisp.el
index c3d5705531e..0ddae24d577 100644
--- a/lisp/ls-lisp.el
+++ b/lisp/ls-lisp.el
@@ -669,7 +669,7 @@ SWITCHES is a list of characters.  Default sorting is alphabetic."
                 ))))
   ;; Finally reverse file alist if necessary.
   ;; (eq below MUST compare `(not (memq ...))' to force comparison of
-  ;; `t' or `nil', rather than list tails!)
+  ;; t or nil, rather than list tails!)
   (if (eq (eq (not (memq ?U switches))  ; unsorted order is reversed
               (not (memq ?r switches))) ; reversed sort order requested
           ls-lisp-dirs-first)           ; already reversed
diff --git a/lisp/mail/mailalias.el b/lisp/mail/mailalias.el
index 48329167bf1..577cec0fd86 100644
--- a/lisp/mail/mailalias.el
+++ b/lisp/mail/mailalias.el
@@ -77,7 +77,7 @@ If not on matching header, `mail-complete-function' gets called instead."
 ;;;###autoload
 (defcustom mail-complete-style 'angles
   "Specifies how \\[mail-complete] formats the full name when it completes.
-If `nil', they contain just the return address like:
+If nil, they contain just the return address like:
         king@grassland.com
 If `parens', they look like:
         king@grassland.com (Elvis Parsley)
diff --git a/lisp/mail/sendmail.el b/lisp/mail/sendmail.el
index 9fa7aa5a6f2..ddd8697dcd6 100644
--- a/lisp/mail/sendmail.el
+++ b/lisp/mail/sendmail.el
@@ -58,7 +58,7 @@
 (defcustom mail-from-style 'default
   "Specifies how \"From:\" fields look.
 
-If `nil', they contain just the return address like:
+If nil, they contain just the return address like:
         king@grassland.com
 If `parens', they look like:
         king@grassland.com (Elvis Parsley)
diff --git a/lisp/mail/uudecode.el b/lisp/mail/uudecode.el
index 419aefbdad0..c1e3439a5de 100644
--- a/lisp/mail/uudecode.el
+++ b/lisp/mail/uudecode.el
@@ -102,7 +102,7 @@ used is specified by `uudecode-decoder-program'."
         (let ((cdir default-directory)
               (default-process-coding-system
                 (if (featurep 'xemacs)
-                    ;; In XEmacs, `nil' is not a valid coding system.
+                    ;; In XEmacs, nil is not a valid coding system.
                     '(binary . binary)
                   nil)))
           (unwind-protect
diff --git a/lisp/net/ange-ftp.el b/lisp/net/ange-ftp.el
index 52153ad8322..1f893a72f8e 100644
--- a/lisp/net/ange-ftp.el
+++ b/lisp/net/ange-ftp.el
@@ -193,7 +193,7 @@
 ;;
 ;;    "^$*$ *"
 ;;
-;; 9) Set the variable ange-ftp-gateway-program-interactive to 't' to let
+;; 9) Set the variable ange-ftp-gateway-program-interactive to t to let
 ;;    ange-ftp know that it has to "hand-hold" the login to the gateway
 ;;    machine.
 ;;
diff --git a/lisp/net/dbus.el b/lisp/net/dbus.el
index 474a48ff276..8f7754137cb 100644
--- a/lisp/net/dbus.el
+++ b/lisp/net/dbus.el
@@ -813,7 +813,7 @@ discovering the still incomplete interface."
   "Unregister OBJECT from D-Bus.
 OBJECT must be the result of a preceding `dbus-register-method',
 `dbus-register-property' or `dbus-register-signal' call.  It
-returns `t' if OBJECT has been unregistered, `nil' otherwise.
+returns t if OBJECT has been unregistered, nil otherwise.
 
 When OBJECT identifies the last method or property, which is
 registered for the respective service, Emacs releases its
@@ -1092,7 +1092,7 @@ well formed."
 (defun dbus-list-activatable-names (&optional bus)
   "Return the D-Bus service names which can be activated as list.
 If BUS is left nil, `:system' is assumed.  The result is a list
-of strings, which is `nil' when there are no activatable service
+of strings, which is nil when there are no activatable service
 names at all."
   (dbus-ignore-errors
     (dbus-call-method
@@ -1101,7 +1101,7 @@ names at all."
 
 (defun dbus-list-names (bus)
   "Return the service names registered at D-Bus BUS.
-The result is a list of strings, which is `nil' when there are no
+The result is a list of strings, which is nil when there are no
 registered service names at all.  Well known names are strings
 like \"org.freedesktop.DBus\".  Names starting with \":\" are
 unique names for services."
@@ -1119,7 +1119,7 @@ A service has a known name if it doesn't start with \":\"."
 
 (defun dbus-list-queued-owners (bus service)
   "Return the unique names registered at D-Bus BUS and queued for SERVICE.
-The result is a list of strings, or `nil' when there are no
+The result is a list of strings, or nil when there are no
 queued name owners service names at all."
   (dbus-ignore-errors
     (dbus-call-method
@@ -1128,7 +1128,7 @@ queued name owners service names at all."
 
 (defun dbus-get-name-owner (bus service)
   "Return the name owner of SERVICE registered at D-Bus BUS.
-The result is either a string, or `nil' if there is no name owner."
+The result is either a string, or nil if there is no name owner."
   (dbus-ignore-errors
     (dbus-call-method
      bus dbus-service-dbus dbus-path-dbus
@@ -1145,7 +1145,7 @@ apply
 
   \(member service \(dbus-list-known-names bus))"
   ;; "Ping" raises a D-Bus error if SERVICE does not exist.
-  ;; Otherwise, it returns silently with `nil'.
+  ;; Otherwise, it returns silently with nil.
   (condition-case nil
       (not
        (if (natnump timeout)
@@ -1335,7 +1335,7 @@ object can contain \"annotation\" children."
 (defun dbus-introspect-get-annotation-names
   (bus service path interface &optional name)
   "Return all annotation names as list of strings.
-If NAME is `nil', the annotations are children of INTERFACE,
+If NAME is nil, the annotations are children of INTERFACE,
 otherwise NAME must be a \"method\", \"signal\", or \"property\"
 object, where the annotations belong to."
   (let ((object
@@ -1352,7 +1352,7 @@ object, where the annotations belong to."
 (defun dbus-introspect-get-annotation
   (bus service path interface name annotation)
   "Return ANNOTATION as XML object.
-If NAME is `nil', ANNOTATION is a child of INTERFACE, otherwise
+If NAME is nil, ANNOTATION is a child of INTERFACE, otherwise
 NAME must be the name of a \"method\", \"signal\", or
 \"property\" object, where the ANNOTATION belongs to."
   (let ((elt (xml-get-children
@@ -1376,7 +1376,7 @@ NAME must be the name of a \"method\", \"signal\", or
   "Return a list of all argument names as list of strings.
 NAME must be a \"method\" or \"signal\" object.
 
-Argument names are optional, the function can return `nil'
+Argument names are optional, the function can return nil
 therefore, even if the method or signal has arguments."
   (let ((object
          (or (dbus-introspect-get-method bus service path interface name)
@@ -1404,9 +1404,9 @@ element of the list returned by `dbus-introspect-get-argument-names'."
   (bus service path interface name &optional direction)
   "Return signature of a `method' or `signal', represented by NAME, as string.
 If NAME is a `method', DIRECTION can be either \"in\" or \"out\".
-If DIRECTION is `nil', \"in\" is assumed.
+If DIRECTION is nil, \"in\" is assumed.
 
-If NAME is a `signal', and DIRECTION is non-`nil', DIRECTION must
+If NAME is a `signal', and DIRECTION is non-nil, DIRECTION must
 be \"out\"."
   ;; For methods, we use "in" as default direction.
   (let ((object (or (dbus-introspect-get-method
@@ -1440,7 +1440,7 @@ be \"out\"."
 (defun dbus-get-property (bus service path interface property)
   "Return the value of PROPERTY of INTERFACE.
 It will be checked at BUS, SERVICE, PATH.  The result can be any
-valid D-Bus value, or `nil' if there is no PROPERTY."
+valid D-Bus value, or nil if there is no PROPERTY."
   (dbus-ignore-errors
    ;; "Get" returns a variant, so we must use the `car'.
    (car
@@ -1451,7 +1451,7 @@ valid D-Bus value, or `nil' if there is no PROPERTY."
 (defun dbus-set-property (bus service path interface property value)
   "Set value of PROPERTY of INTERFACE to VALUE.
 It will be checked at BUS, SERVICE, PATH.  When the value has
-been set successful, the result is VALUE.  Otherwise, `nil' is
+been set successful, the result is VALUE.  Otherwise, nil is
 returned."
   (dbus-ignore-errors
    ;; "Set" requires a variant.
@@ -1465,7 +1465,7 @@ returned."
   "Return all properties of INTERFACE at BUS, SERVICE, PATH.
 The result is a list of entries.  Every entry is a cons of the
 name of the property, and its value.  If there are no properties,
-`nil' is returned."
+nil is returned."
   (dbus-ignore-errors
     ;; "GetAll" returns "a{sv}".
     (let (result)
diff --git a/lisp/net/network-stream.el b/lisp/net/network-stream.el
index 0104fa7dd12..1eb5342009c 100644
--- a/lisp/net/network-stream.el
+++ b/lisp/net/network-stream.el
@@ -121,7 +121,7 @@ values:
 
 :client-certificate should either be a list where the first
   element is the certificate key file name, and the second
-  element is the certificate file name itself, or `t', which
+  element is the certificate file name itself, or t, which
   means that `auth-source' will be queried for the key and the
   certificate.  This parameter will only be used when doing TLS
   or STARTTLS connections.
diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
index 11db7a2cab2..852d2941f0b 100644
--- a/lisp/net/rcirc.el
+++ b/lisp/net/rcirc.el
@@ -1372,7 +1372,7 @@ if ARG is omitted or nil."
     (t         . "%fp*** %fs%n %r %m"))
   "An alist of formats used for printing responses.
 The format is looked up using the response-type as a key;
-if no match is found, the default entry (with a key of `t') is used.
+if no match is found, the default entry (with a key of t) is used.
 
 The entry's value part should be a string, which is inserted with
 the of the following escape sequences replaced by the described values:
diff --git a/lisp/net/secrets.el b/lisp/net/secrets.el
index 56cbec4ea75..c4102a18cef 100644
--- a/lisp/net/secrets.el
+++ b/lisp/net/secrets.el
@@ -85,7 +85,7 @@
 ;; temporarily.  This shall be preferred over creation of a persistent
 ;; collection, when the information shall not live longer than Emacs.
 ;; The session collection can be addressed either by the string
-;; "session", or by `nil', whenever a collection parameter is needed.
+;; "session", or by nil, whenever a collection parameter is needed.
 
 ;; As already said, a collection is a group of secret items.  A secret
 ;; item has a label, the "secret" (which is a string), and a set of
@@ -418,7 +418,7 @@ returned, and it will be stored in `secrets-session-path'."
 (defun secrets-prompt-handler (&rest args)
   "Handler for signals emitted by `secrets-interface-prompt'."
   ;; An empty object path is always identified as `secrets-empty-path'
-  ;; or `nil'.  Either we set it explicitly, or it is returned by the
+  ;; or nil.  Either we set it explicitly, or it is returned by the
   ;; "Completed" signal.
   (if (car args) ;; dismissed
       (setq secrets-prompt-signal (list secrets-empty-path))
diff --git a/lisp/net/tramp-adb.el b/lisp/net/tramp-adb.el
index a92ca4df51c..7c509e1d098 100644
--- a/lisp/net/tramp-adb.el
+++ b/lisp/net/tramp-adb.el
@@ -850,9 +850,9 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
       (when tmpinput (delete-file tmpinput))
 
       ;; `process-file-side-effects' has been introduced with GNU
-      ;; Emacs 23.2.  If set to `nil', no remote file will be changed
+      ;; Emacs 23.2.  If set to nil, no remote file will be changed
       ;; by `program'.  If it doesn't exist, we assume its default
-      ;; value 't'.
+      ;; value t.
       (unless (and (boundp 'process-file-side-effects)
                    (not (symbol-value 'process-file-side-effects)))
         (tramp-flush-directory-property v ""))
diff --git a/lisp/net/tramp-compat.el b/lisp/net/tramp-compat.el
index 3ec90ca556f..e68c81cfa70 100644
--- a/lisp/net/tramp-compat.el
+++ b/lisp/net/tramp-compat.el
@@ -100,7 +100,7 @@
     (setq byte-compile-not-obsolete-vars '(directory-sep-char)))
 
   ;; `remote-file-name-inhibit-cache' has been introduced with Emacs 24.1.
-  ;; Besides `t', `nil', and integer, we use also timestamps (as
+  ;; Besides t, nil, and integer, we use also timestamps (as
   ;; returned by `current-time') internally.
   (unless (boundp 'remote-file-name-inhibit-cache)
     (defvar remote-file-name-inhibit-cache nil))
@@ -459,7 +459,7 @@ element is not omitted."
   (delete "" (split-string string pattern)))
 
 (defun tramp-compat-process-running-p (process-name)
-  "Returns `t' if system process PROCESS-NAME is running for `user-login-name'."
+  "Returns t if system process PROCESS-NAME is running for `user-login-name'."
   (when (stringp process-name)
     (cond
      ;; GNU Emacs 22 on w32.
diff --git a/lisp/net/tramp-gvfs.el b/lisp/net/tramp-gvfs.el
index 5988a284c6e..215e39d04c3 100644
--- a/lisp/net/tramp-gvfs.el
+++ b/lisp/net/tramp-gvfs.el
@@ -1563,7 +1563,7 @@ connection if a previous connection has died for some reason."
 (defun tramp-gvfs-send-command (vec command &rest args)
   "Send the COMMAND with its ARGS to connection VEC.
 COMMAND is usually a command from the gvfs-* utilities.
-`call-process' is applied, and it returns `t' if the return code is zero."
+`call-process' is applied, and it returns t if the return code is zero."
   (with-current-buffer (tramp-get-connection-buffer vec)
     (tramp-gvfs-maybe-open-connection vec)
     (erase-buffer)
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 3f006e84dc1..acb97e880b4 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -1558,7 +1558,7 @@ be non-negative integers."
         (progn
           (tramp-set-file-property v localname "file-acl" acl-string)
           t)
-      ;; In case of errors, we return `nil'.
+      ;; In case of errors, we return nil.
       (tramp-set-file-property v localname "file-acl-string" 'undef)
       nil)))
 
@@ -3103,9 +3103,9 @@ the result will be a local, non-Tramp, file name."
       (when tmpinput (delete-file tmpinput))
 
       ;; `process-file-side-effects' has been introduced with GNU
-      ;; Emacs 23.2.  If set to `nil', no remote file will be changed
+      ;; Emacs 23.2.  If set to nil, no remote file will be changed
       ;; by `program'.  If it doesn't exist, we assume its default
-      ;; value `t'.
+      ;; value t.
       (unless (and (boundp 'process-file-side-effects)
                    (not (symbol-value 'process-file-side-effects)))
         (tramp-flush-directory-property v ""))
@@ -4973,8 +4973,8 @@ function waits for output unless NOOUTPUT is set."
   (vec command &optional subshell dont-suppress-err)
   "Run COMMAND and check its exit status.
 Sends `echo $?' along with the COMMAND for checking the exit status.
-If COMMAND is nil, just sends `echo $?'.  Returns `t' if the exit
-status is 0, and `nil' otherwise.
+If COMMAND is nil, just sends `echo $?'.  Returns t if the exit
+status is 0, and nil otherwise.
 
 If the optional argument SUBSHELL is non-nil, the command is
 executed in a subshell, ie surrounded by parentheses.  If
@@ -5551,7 +5551,7 @@ If no corresponding command is found, nil is returned.
 Otherwise, either a string is returned which contains a `%s' mark
 to be used for the respective input or output file; or a Lisp
 function cell is returned to be applied on a buffer."
-  ;; We must catch the errors, because we want to return `nil', when
+  ;; We must catch the errors, because we want to return nil, when
   ;; no inline coding is found.
   (ignore-errors
     (let ((coding
diff --git a/lisp/net/tramp-smb.el b/lisp/net/tramp-smb.el
index 14360b96fe6..c4f0f1f500a 100644
--- a/lisp/net/tramp-smb.el
+++ b/lisp/net/tramp-smb.el
@@ -1242,9 +1242,9 @@ target of the symlink differ."
         (kill-buffer (tramp-get-connection-property v "process-buffer" nil)))
 
       ;; `process-file-side-effects' has been introduced with GNU
-      ;; Emacs 23.2.  If set to `nil', no remote file will be changed
+      ;; Emacs 23.2.  If set to nil, no remote file will be changed
       ;; by `program'.  If it doesn't exist, we assume its default
-      ;; value `t'.
+      ;; value t.
       (unless (and (boundp 'process-file-side-effects)
                    (not (symbol-value 'process-file-side-effects)))
         (tramp-flush-directory-property v ""))
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index f4ece9000a6..95f54490cac 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -1034,7 +1034,7 @@ The timeout does not include the time reading a password."
 This is necessary as self defense mechanism, in order to avoid
 yo-yo connection attempts when the remote host is unavailable.
 
-A value of 0 or `nil' suppresses this check.  This might be
+A value of 0 or nil suppresses this check.  This might be
 necessary, when several out-of-order copy operations are
 performed, or when several asynchronous processes will be started
 in a short time frame.  In those cases it is recommended to
@@ -1049,8 +1049,8 @@ A remote directory might have changed its contents.  In order to
 make it visible during file name completion in the minibuffer,
 Tramp flushes its cache and rereads the directory contents when
 more than `tramp-completion-reread-directory-timeout' seconds
-have been gone since last remote command execution.  A value of `t'
-would require an immediate reread during filename completion, `nil'
+have been gone since last remote command execution.  A value of t
+would require an immediate reread during filename completion, nil
 means to use always cached values for the directory contents."
   :group 'tramp
   :type '(choice (const nil) (const t) integer))
@@ -3314,7 +3314,7 @@ User is always nil."
 
 (defun tramp-handle-unhandled-file-name-directory (_filename)
   "Like `unhandled-file-name-directory' for Tramp files."
-  ;; Starting with Emacs 23, we must simply return `nil'.  But we must
+  ;; Starting with Emacs 23, we must simply return nil.  But we must
   ;; keep backward compatibility, also with XEmacs.  "~/" cannot be
   ;; returned, because there might be machines without a HOME
   ;; directory (like hydra).
@@ -3737,7 +3737,7 @@ Example:
 
   (tramp-equal-remote \"/ssh::/etc\" \"/<your host name>:/home\")
 
-would yield `t'.  On the other hand, the following check results in nil:
+would yield t.  On the other hand, the following check results in nil:
 
   (tramp-equal-remote \"/sudo::/etc\" \"/su::/etc\")"
   (and (tramp-tramp-file-p file1)
diff --git a/lisp/obsolete/xesam.el b/lisp/obsolete/xesam.el
index 4ee8c6f1b0f..39dd6a241f2 100644
--- a/lisp/obsolete/xesam.el
+++ b/lisp/obsolete/xesam.el
@@ -378,7 +378,7 @@ If PROPERTY is not existing, retrieve it from ENGINE first."
 (defun xesam-search-engines ()
   "Return Xesam search engines, stored in `xesam-search-engines'.
 The first search engine is the name owner of `xesam-service-search'.
-If there is no registered search engine at all, the function returns `nil'."
+If there is no registered search engine at all, the function returns nil."
   (let ((services (dbus-ignore-errors
                     (dbus-list-queued-owners
                      :session xesam-service-search)))
diff --git a/lisp/org/ob-ruby.el b/lisp/org/ob-ruby.el
index 7e09d6d78be..8dee01a5389 100644
--- a/lisp/org/ob-ruby.el
+++ b/lisp/org/ob-ruby.el
@@ -58,7 +58,7 @@
   :type 'string)
 
 (defcustom org-babel-ruby-nil-to 'hline
-  "Replace 'nil' in ruby tables with this before returning."
+  "Replace nil in ruby tables with this before returning."
   :group 'org-babel
   :version "24.4"
   :package-version '(Org . "8.0")
diff --git a/lisp/org/org-agenda.el b/lisp/org/org-agenda.el
index 8f7611fd1ff..65696b21d71 100644
--- a/lisp/org/org-agenda.el
+++ b/lisp/org/org-agenda.el
@@ -6642,7 +6642,7 @@ The modified list may contain inherited tags, and tags matched by
 
 LIST is the list of agenda items formatted by `org-agenda-list'.
 NDAYS is the span of the current agenda view.
-TODAYP is `t' when the current agenda view is on today."
+TODAYP is t when the current agenda view is on today."
   (catch 'exit
     (cond ((not org-agenda-use-time-grid) (throw 'exit list))
           ((and todayp (member 'today (car org-agenda-time-grid))))
diff --git a/lisp/org/org-capture.el b/lisp/org/org-capture.el
index 7f1f7ed8af1..64e30152a5b 100644
--- a/lisp/org/org-capture.el
+++ b/lisp/org/org-capture.el
@@ -201,7 +201,7 @@ properties are:
 
  :clock-resume       Start the interrupted clock when finishing the capture.
                      Note that :clock-keep has precedence over :clock-resume.
-                     When setting both to `t', the current clock will run and
+                     When setting both to t, the current clock will run and
                      the previous one will not be resumed.
 
  :unnarrowed         Do not narrow the target buffer, simply show the
diff --git a/lisp/org/org-gnus.el b/lisp/org/org-gnus.el
index 880994a8fa9..8b616f0a0ff 100644
--- a/lisp/org/org-gnus.el
+++ b/lisp/org/org-gnus.el
@@ -60,7 +60,7 @@ Normally, this translation is done by querying the IMAP server,
 which is usually very fast.  Unfortunately, some (maybe badly
 configured) IMAP servers don't support this operation quickly.
 So if following a link to a Gnus article takes ages, try setting
-this variable to `t'."
+this variable to t."
   :group 'org-link-store
   :version "24.1"
   :type 'boolean)
diff --git a/lisp/org/org-macs.el b/lisp/org/org-macs.el
index db09909f404..ea8e7b532aa 100644
--- a/lisp/org/org-macs.el
+++ b/lisp/org/org-macs.el
@@ -55,7 +55,7 @@
      ,@body))
 
 (defmacro org-called-interactively-p (&optional kind)
-  (declare (debug (&optional ("quote" symbolp)))) ;Why not just `t'?
+  (declare (debug (&optional ("quote" symbolp)))) ;Why not just t?
   (if (featurep 'xemacs)
       `(interactive-p)
     (if (or (> emacs-major-version 23)
diff --git a/lisp/org/org-protocol.el b/lisp/org/org-protocol.el
index eeefc8da528..d0750f7d639 100644
--- a/lisp/org/org-protocol.el
+++ b/lisp/org/org-protocol.el
@@ -561,7 +561,7 @@ as filename."
         (let ((fname  (expand-file-name (car var))))
           (setq fname (org-protocol-check-filename-for-protocol
                        fname (member var flist)  client))
-          (if (eq fname t) ;; greedy? We need the `t' return value.
+          (if (eq fname t) ;; greedy? We need the t return value.
               (progn
                 (ad-set-arg 0 nil)
                 (throw 'greedy t))
diff --git a/lisp/org/org.el b/lisp/org/org.el
index ea5d56effcd..29ef8efb640 100644
--- a/lisp/org/org.el
+++ b/lisp/org/org.el
@@ -595,7 +595,7 @@ XEmacs user should have this variable set to nil, because
 (defcustom org-loop-over-headlines-in-active-region nil
   "Shall some commands act upon headlines in the active region?
 
-When set to `t', some commands will be performed in all headlines
+When set to t, some commands will be performed in all headlines
 within the active region.
 
 When set to `start-level', some commands will be performed in all
@@ -1575,7 +1575,7 @@ See the manual for examples."
   "Non-nil means Org will display descriptive links.
 E.g. [[http://orgmode.org][Org website]] will be displayed as
 \"Org Website\", hiding the link itself and just displaying its
-description.  When set to `nil', Org will display the full links
+description.  When set to nil, Org will display the full links
 literally.
 
 You can interactively set the value of this variable by calling
@@ -11558,7 +11558,7 @@ go to the location where the last refiling operation has put the subtree.
 With a numeric prefix argument of `2', refile to the running clock.
 
 With a numeric prefix argument of `3', emulate `org-refile-keep'
-being set to `t' and copy to the target location, don't move it.
+being set to t and copy to the target location, don't move it.
 Beware that keeping refiled entries may result in duplicated ID
 properties.
 
@@ -15541,7 +15541,7 @@ and the new value.")
 
 (defun org-entry-put (pom property value)
   "Set PROPERTY to VALUE for entry at point-or-marker POM.
-If the value is `nil', it is converted to the empty string.
+If the value is nil, it is converted to the empty string.
 If it is not a string, an error is raised."
   (cond ((null value) (setq value ""))
         ((not (stringp value))
@@ -17749,7 +17749,7 @@ If no number is found, the return value is 0."
 (defcustom org-image-actual-width t
   "Should we use the actual width of images when inlining them?
 
-When set to `t', always use the image width.
+When set to t, always use the image width.
 
 When set to a number, use imagemagick (when available) to set
 the image's width to this value.
@@ -17776,7 +17776,7 @@ This requires Emacs >= 24.1, build with imagemagick support."
 
 (defcustom org-agenda-inhibit-startup nil
   "Inhibit startup when preparing agenda buffers.
-When this variable is `t', the initialization of the Org agenda
+When this variable is t, the initialization of the Org agenda
 buffers is inhibited: e.g. the visibility state is not set, the
 tables are not re-aligned, etc."
   :type 'boolean
diff --git a/lisp/org/ox-odt.el b/lisp/org/ox-odt.el
index 6c74fb3eabd..f1ef90e169b 100644
--- a/lisp/org/ox-odt.el
+++ b/lisp/org/ox-odt.el
@@ -847,7 +847,7 @@ TABLE-CELL-STYLE-SELECTOR := `use-first-row-styles'       |
                              `use-banding-rows-styles'    |
                              `use-banding-columns-styles' |
                              `use-first-row-styles'
-ON-OR-OFF                 := `t' | `nil'
+ON-OR-OFF                 := t | nil
 
 For example, with the following configuration
 
@@ -3261,7 +3261,7 @@ contextual information."
   "Retrieve styles applicable to a table cell.
 R and C are (zero-based) row and column numbers of the table
 cell.  STYLE-SPEC is an entry in `org-odt-table-styles'
-applicable to the current table.  It is `nil' if the table is not
+applicable to the current table.  It is nil if the table is not
 associated with any style attributes.
 
 Return a cons of (TABLE-CELL-STYLE-NAME . PARAGRAPH-STYLE-NAME).
diff --git a/lisp/org/ox-texinfo.el b/lisp/org/ox-texinfo.el
index 0c81b620618..26f58ad662a 100644
--- a/lisp/org/ox-texinfo.el
+++ b/lisp/org/ox-texinfo.el
@@ -117,7 +117,7 @@
 (defcustom org-texinfo-coding-system nil
   "Default document encoding for Texinfo output.
 
-If `nil' it will default to `buffer-file-coding-system'."
+If nil it will default to `buffer-file-coding-system'."
   :group 'org-export-texinfo
   :type 'coding-system)
 
diff --git a/lisp/progmodes/ada-xref.el b/lisp/progmodes/ada-xref.el
index 6b611e6f99b..771dc2a3da1 100644
--- a/lisp/progmodes/ada-xref.el
+++ b/lisp/progmodes/ada-xref.el
@@ -954,7 +954,7 @@ Return new value of PROJECT."
         (append (mapcar 'directory-file-name compilation-search-path)
                 ada-search-directories))
 
-  ;; return 't', for decent display in message buffer when called interactively
+  ;; return t, for decent display in message buffer when called interactively
   t)
 
 (defun ada-find-references (&optional pos arg local-only)
diff --git a/lisp/progmodes/cc-defs.el b/lisp/progmodes/cc-defs.el
index d8854f4b882..fd4bfb3b921 100644
--- a/lisp/progmodes/cc-defs.el
+++ b/lisp/progmodes/cc-defs.el
@@ -2017,10 +2017,10 @@ The second argument can optionally be a docstring.  The rest of the
 arguments are one or more repetitions of LANG VAL where LANG specifies
 the language(s) that VAL applies to.  LANG is the name of the
 language, i.e. the mode name without the \"-mode\" suffix, or a list
-of such language names, or `t' for all languages.  VAL is a form to
+of such language names, or t for all languages.  VAL is a form to
 evaluate to get the value.
 
-If LANG isn't `t' or one of the core languages in CC Mode, it must
+If LANG isn't t or one of the core languages in CC Mode, it must
 have been declared with `c-add-language'.
 
 Neither NAME, LANG nor VAL are evaluated directly - they should not be
@@ -2030,7 +2030,7 @@ VAL to evaluate parts of it directly.
 When VAL is evaluated for some language, that language is temporarily
 made current so that `c-lang-const' without an explicit language can
 be used inside VAL to refer to the value of a language constant in the
-same language.  That is particularly useful if LANG is `t'.
+same language.  That is particularly useful if LANG is t.
 
 VAL is not evaluated right away but rather when the value is requested
 with `c-lang-const'.  Thus it's possible to use `c-lang-const' inside
@@ -2365,7 +2365,7 @@ fallback definition for all modes, to break the cycle).")
 
 (defun c-find-assignment-for-mode (source-pos mode match-any-lang _name)
   ;; Find the first assignment entry that applies to MODE at or after
-  ;; SOURCE-POS.  If MATCH-ANY-LANG is non-nil, entries with `t' as
+  ;; SOURCE-POS.  If MATCH-ANY-LANG is non-nil, entries with t as
   ;; the language list are considered to match, otherwise they don't.
   ;; On return SOURCE-POS is updated to point to the next assignment
   ;; after the returned one.  If no assignment is found,
diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 823d795b6de..06b03a24bd6 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -7972,7 +7972,7 @@ comment at the start of cc-engine.el for more info."
   ;; This should be called with point inside an argument list.
   ;;
   ;; Only one level of enclosing parentheses is considered, so for
-  ;; instance `nil' is returned when in a function call within an asm
+  ;; instance nil is returned when in a function call within an asm
   ;; operand.
   ;;
   ;; This function might do hidden buffer changes.
diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index 44172b05a56..ad564f7c3df 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -1772,8 +1772,8 @@ on level 2 only and so aren't combined with `c-complex-decl-matchers'."
 ;;                     "\\|"
 ;;                     (c-lang-const c-symbol-key)
 ;;                     "\\)")
-;;             `((c-font-lock-declarators limit t nil) ; That `nil' says use `font-lock-variable-name-face';
-;;                                      ; `t' would mean `font-lock-function-name-face'.
+;;             `((c-font-lock-declarators limit t nil) ; That nil says use `font-lock-variable-name-face';
+;;                                      ; t would mean `font-lock-function-name-face'.
 ;;               (progn
 ;;                 (c-put-char-property (match-beginning 0) 'c-type
 ;;                                      'c-decl-id-start)
diff --git a/lisp/progmodes/cc-guess.el b/lisp/progmodes/cc-guess.el
index 20534737d8a..ba23a75ff22 100644
--- a/lisp/progmodes/cc-guess.el
+++ b/lisp/progmodes/cc-guess.el
@@ -91,7 +91,7 @@ The offset of a line included in the indent information returned by
 (defcustom c-guess-region-max 50000
   "The maximum region size for examining indent information with `c-guess'.
 It takes a long time to examine indent information from a large region;
-this option helps you limit that time. `nil' means no limit."
+this option helps you limit that time. nil means no limit."
   :version "24.1"
   :type 'integer
   :group 'c)
@@ -465,7 +465,7 @@ the absolute file name of the file if STYLE-NAME is nil."
 (defun c-guess-dump-guessed-style (&optional printer)
   "Show the guessed style.
 `pp' is used to print the style but if PRINTER is given,
-PRINTER is used instead. If PRINTER is not `nil', it
+PRINTER is used instead. If PRINTER is not nil, it
 is called with one argument, the guessed style."
   (interactive)
   (let ((style (c-guess-make-style c-guess-guessed-basic-offset
diff --git a/lisp/progmodes/cperl-mode.el b/lisp/progmodes/cperl-mode.el
index 2acfc104cf3..d6f6f3b25b0 100644
--- a/lisp/progmodes/cperl-mode.el
+++ b/lisp/progmodes/cperl-mode.el
@@ -282,7 +282,7 @@ This is in addition to cperl-continued-statement-offset."
 
 (defcustom cperl-indent-wrt-brace t
   "*Non-nil means indent statements in if/etc block relative brace, not if/etc.
-Versions 5.2 ... 5.20 behaved as if this were `nil'."
+Versions 5.2 ... 5.20 behaved as if this were nil."
   :type 'boolean
   :group 'cperl-indentation-details)
 
diff --git a/lisp/progmodes/idlw-shell.el b/lisp/progmodes/idlw-shell.el
index 023970207dc..23f9d4af8c9 100644
--- a/lisp/progmodes/idlw-shell.el
+++ b/lisp/progmodes/idlw-shell.el
@@ -2638,7 +2638,7 @@ If ENABLE is non-nil, enable them instead."
 (defun idlwave-shell-break-in ()
   "Look for a module name near point and set a break point for it.
 The command looks for an identifier near point and sets a breakpoint
-for the first line of the corresponding module.  If MODULE is `t', set
+for the first line of the corresponding module.  If MODULE is t, set
 in the current routine."
   (interactive)
   (let* ((module (idlwave-fix-module-if-obj_new (idlwave-what-module)))
diff --git a/lisp/progmodes/idlwave.el b/lisp/progmodes/idlwave.el
index 45f080c3aab..44d84d65810 100644
--- a/lisp/progmodes/idlwave.el
+++ b/lisp/progmodes/idlwave.el
@@ -8162,7 +8162,7 @@ demand _EXTRA in the keyword list."
                                class
                                (idlwave-routines)) 'do-link))))))
 
-    ;; If the class is `t', combine all keywords of all methods NAME
+    ;; If the class is t, combine all keywords of all methods NAME
     (when (eq class t)
       (mapc (lambda (entry)
               (and
diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 4b0a028faa3..d45d082c40a 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -3216,7 +3216,7 @@ With argument MSG show activation/deactivation message."
            (concat
             "Your `python-shell-interpreter' doesn't seem to "
             "support readline, yet `python-shell-completion-native' "
-            (format "was `t' and %S is not part of the "
+            (format "was t and %S is not part of the "
                     (file-name-nondirectory python-shell-interpreter))
             "`python-shell-completion-native-disabled-interpreters' "
             "list.  Native completions have been disabled locally. "))
diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index 0e2f66e5bc5..21ad1021c9e 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -287,7 +287,7 @@ Only has effect when `ruby-use-smie' is nil."
   :group 'ruby
   :safe 'booleanp)
 
-;; FIXME Woefully under documented.  What is the point of the last `t'?.
+;; FIXME Woefully under documented.  What is the point of the last t?.
 (defcustom ruby-deep-indent-paren '(?\( ?\[ ?\] t)
   "Deep indent lists in parenthesis when non-nil.
 The value t means continuous line.
diff --git a/lisp/ps-print.el b/lisp/ps-print.el
index 0a2c214690f..e76b332ee3c 100644
--- a/lisp/ps-print.el
+++ b/lisp/ps-print.el
@@ -809,7 +809,7 @@ Please send all bug fixes and enhancements to
 ;; on next page.  Visually, valid values are (the character `+' at right of
 ;; each column indicates that a line is printed):
 ;;
-;;                 `nil'        `follow'        `full'        `full-follow'
+;;                  nil         `follow'        `full'        `full-follow'
 ;; Current Page --------     -----------     ---------     ----------------
 ;;              1  XXXXX +   1  XXXXXXXX +   1  XXXXXX +   1  XXXXXXXXXXXXX +
 ;;              2  XXXXX +   2  XXXXXXXX +   2  XXXXXX +   2  XXXXXXXXXXXXX +
@@ -2117,7 +2117,7 @@ See also documentation for `ps-zebra-stripes' and `ps-zebra-stripe-height'."
 Visually, valid values are (the character `+' at right of each column indicates
 that a line is printed):
 
-                   `nil'        `follow'        `full'        `full-follow'
+                    nil         `follow'        `full'        `full-follow'
    Current Page --------     -----------     ---------     ----------------
                 1  XXXXX +   1  XXXXXXXX +   1  XXXXXX +   1  XXXXXXXXXXXXX +
                 2  XXXXX +   2  XXXXXXXX +   2  XXXXXX +   2  XXXXXXXXXXXXX +
diff --git a/lisp/ses.el b/lisp/ses.el
index 3336769270c..e625e4ed593 100644
--- a/lisp/ses.el
+++ b/lisp/ses.el
@@ -2276,7 +2276,7 @@ to are recalculated first."
     (when (and (< col (1- ses--numcols)) ;;Last column can't spill over, anyway
                (eq (ses-cell-value row (1+ col)) '*skip*))
       ;; This cell has spill-over.  We'll momentarily pretend the following cell
-      ;; has a `t' in it.
+      ;; has a t in it.
       (cl-progv
           (list (ses-cell-symbol row (1+ col)))
           '(t)
@@ -3528,11 +3528,11 @@ execution anyway.  Always returns t if `safe-functions' is t."
 ;;----------------------------------------------------------------------------
 
 (defun ses--clean-! (&rest x)
-  "Clean by `delq' list X from any occurrence of `nil' or `*skip*'."
+  "Clean by `delq' list X from any occurrence of nil or `*skip*'."
   (delq nil (delq '*skip* x)))
 
 (defun ses--clean-_ (x y)
-  "Clean list X  by replacing by Y any occurrence of `nil' or `*skip*'.
+  "Clean list X  by replacing by Y any occurrence of nil or `*skip*'.
 
 This will change X by making `setcar' on its cons cells."
   (let ((ret x) ret-elt)
diff --git a/lisp/simple.el b/lisp/simple.el
index dfd92dcdc05..49a95aea4a8 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -3488,9 +3488,9 @@ value passed."
 (defvar process-file-side-effects t
   "Whether a call of `process-file' changes remote files.
 
-By default, this variable is always set to `t', meaning that a
+By default, this variable is always set to t, meaning that a
 call of `process-file' could potentially change any file on a
-remote host.  When set to `nil', a file handler could optimize
+remote host.  When set to nil, a file handler could optimize
 its behavior with respect to remote file attribute caching.
 
 You should only ever change this variable with a let-binding;
@@ -6675,7 +6675,7 @@ beyond `current-fill-column' automatically breaks the line at a
 previous space.
 
 When `auto-fill-mode' is on, the `auto-fill-function' variable is
-non-`nil'.
+non-nil.
 
 The value of `normal-auto-fill-function' specifies the function to use
 for `auto-fill-function' when turning Auto Fill mode on."
@@ -8232,7 +8232,7 @@ version and use the one distributed with Emacs."))
 Each element has the form (PACKAGE SYMBOL REGEXP STRING).
 PACKAGE is either a regular expression to match file names, or a
 symbol (a feature name), like for `with-eval-after-load'.
-SYMBOL is either the name of a string variable, or `t'.  Upon
+SYMBOL is either the name of a string variable, or t.  Upon
 loading PACKAGE, if SYMBOL is t or matches REGEXP, display a
 warning using STRING as the message.")
 
diff --git a/lisp/textmodes/bibtex.el b/lisp/textmodes/bibtex.el
index 10edefc9d3e..9d6d19e6e1e 100644
--- a/lisp/textmodes/bibtex.el
+++ b/lisp/textmodes/bibtex.el
@@ -4338,10 +4338,10 @@ Correct and validate again.\n"
             (goto-char (point-min))
             (forward-line 2)) ; first error message
           (display-buffer err-buf)
-          nil) ; return `nil' (i.e., buffer is invalid)
+          nil) ; return nil (i.e., buffer is invalid)
       (message "%s is syntactically correct"
                (if mark-active "Region" "Buffer"))
-      t))) ; return `t' (i.e., buffer is valid)
+      t))) ; return t (i.e., buffer is valid)
 
 (defun bibtex-validate-globally (&optional strings)
   "Check for duplicate keys in `bibtex-files'.
@@ -4395,9 +4395,9 @@ Return t if test was successful, nil otherwise."
             (goto-char (point-min))
             (forward-line 2)) ; first error message
           (display-buffer err-buf)
-          nil) ; return `nil' (i.e., buffer is invalid)
+          nil) ; return nil (i.e., buffer is invalid)
       (message "No duplicate keys.")
-      t))) ; return `t' (i.e., buffer is valid)
+      t))) ; return t (i.e., buffer is valid)
 
 (defun bibtex-next-field (begin &optional comma)
   "Move point to end of text of next BibTeX field or entry head.
diff --git a/lisp/textmodes/ispell.el b/lisp/textmodes/ispell.el
index e48a70820eb..b0fcb1724f5 100644
--- a/lisp/textmodes/ispell.el
+++ b/lisp/textmodes/ispell.el
@@ -3402,7 +3402,7 @@ Must be called after `ispell-buffer-local-parsing' due to dependence on mode."
 
 (defun ispell-ignore-fcc (start end)
   "Delete the Fcc: message header when large attachments are included.
-Return value `nil' if file with large attachments is saved.
+Return value nil if file with large attachments is saved.
 This can be used to avoid multiple questions for multiple large attachments.
 Returns point to starting location afterwards."
   (let ((result t))
@@ -3900,7 +3900,7 @@ Otherwise, it must be a function which is called to get the limit.")
 
 (defun ispell-mime-multipartp (&optional limit)
   "Return multipart message start boundary or nil if none."
-  ;; caller must ensure `case-fold-search' is set to `t'
+  ;; caller must ensure `case-fold-search' is set to t
   (and
    (re-search-forward
     "Content-Type: *multipart/\\([^ \t\n]*;[ \t]*[\n]?[ \t]*\\)+boundary="
diff --git a/lisp/type-break.el b/lisp/type-break.el
index a5a31c9ffd1..5a12f02f876 100644
--- a/lisp/type-break.el
+++ b/lisp/type-break.el
@@ -45,7 +45,7 @@
 
 ;; If you find echo area messages annoying and would prefer to see messages
 ;; in the mode line instead, do M-x type-break-mode-line-message-mode
-;; or set the variable of the same name to `t'.
+;; or set the variable of the same name to t.
 
 ;; This program can truly cons up a storm because of all the calls to
 ;; `current-time' (which always returns fresh conses).  I'm dismayed by
diff --git a/lisp/vc/compare-w.el b/lisp/vc/compare-w.el
index 07c07682186..5b923697241 100644
--- a/lisp/vc/compare-w.el
+++ b/lisp/vc/compare-w.el
@@ -88,7 +88,7 @@ regexp containing some field separator or a newline, depending on
 the nature of the difference units separator.  The variable can
 be made buffer-local.
 
-If the value of this variable is `nil' (option \"No sync\"), then
+If the value of this variable is nil (option \"No sync\"), then
 no synchronization is performed, and the function `ding' is called
 to beep or flash the screen when points are mismatched."
   :type '(choice function regexp (const :tag "No sync" nil))
diff --git a/lisp/wid-edit.el b/lisp/wid-edit.el
index 0a9578391e0..d09214b42a3 100644
--- a/lisp/wid-edit.el
+++ b/lisp/wid-edit.el
@@ -3319,7 +3319,7 @@ It reads a directory name from an editable text field."
             ;; Avoid a confusing end-of-file error.
             (skip-syntax-forward "\\s-")
             (if (eobp)
-                (setq err "Empty sexp -- use `nil'?")
+                (setq err "Empty sexp -- use nil?")
               (unless (widget-apply widget :match (read (current-buffer)))
                 (setq err (widget-get widget :type-error))))
             ;; Allow whitespace after expression.
diff --git a/lisp/widget.el b/lisp/widget.el
index 539f91e63a0..d62f7ffd8d1 100644
--- a/lisp/widget.el
+++ b/lisp/widget.el
@@ -85,7 +85,7 @@ create identical widgets:
 The third argument DOC is a documentation string for the widget."
   ;;
   (unless (or (null doc) (stringp doc))
-    (error "widget documentation must be `nil' or a string."))
+    (error "widget documentation must be nil or a string."))
   (put name 'widget-type (cons class args))
   (put name 'widget-documentation (purecopy doc))
   name)
diff --git a/lisp/window.el b/lisp/window.el
index c13499f542b..fad9b2f69fa 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -4311,7 +4311,7 @@ one.  If non-nil, reset `quit-restore' parameter to nil.
 Optional second argument BURY-OR-KILL tells how to proceed with
 the buffer of WINDOW.  The following values are handled:
 
-`nil' means to not handle the buffer in a particular way.  This
+nil means to not handle the buffer in a particular way.  This
   means that if WINDOW is not deleted by this function, invoking
   `switch-to-prev-buffer' will usually show the buffer again.
 
@@ -8107,7 +8107,7 @@ This function is responsible for combining the sizes of the
 displayed windows and returning a cons (WIDTH . HEIGHT)
 describing the width and height with which Emacs will call
 `set-process-window-size' for that process.  If the function
-returns `nil', Emacs does not call `set-process-window-size'.
+returns nil, Emacs does not call `set-process-window-size'.
 
 This function is called with the process buffer as the current
 buffer and with two arguments: the process and a list of windows
diff --git a/lisp/woman.el b/lisp/woman.el
index 611ba743652..75c3d2e3822 100644
--- a/lisp/woman.el
+++ b/lisp/woman.el
@@ -161,7 +161,7 @@
 
 ;; The WoMan menu provides an option to make a contents menu for the
 ;; current man page (using imenu).  Alternatively, if you set the
-;; variable `woman-imenu' to `t' then WoMan will do it automatically
+;; variable `woman-imenu' to t then WoMan will do it automatically
 ;; for every man page.  The menu title is the value of the variable
 ;; `woman-imenu-title', which is "CONTENTS" by default.  By default,
 ;; the menu shows manual sections and subsections, but you can change
@@ -179,7 +179,7 @@
 ;; Howard Melman made (essentially) the following suggestions, which
 ;; are slightly different from the expression that I currently use.
 ;; You may prefer one of Howard's suggestions, which I think assume
-;; that `case-fold-search' is `t' (which it is by default):
+;; that `case-fold-search' is t (which it is by default):
 
 ;; (setq woman-imenu-generic-expression
 ;;       '((nil "^\\(   \\)?\\([A-Z][A-Z ]+[A-Z]\\)[ \t]*$" 2)))
@@ -217,7 +217,7 @@
 ;; This is modeled on the byte-compiler.  It logs all files formatted
 ;; by WoMan, and if WoMan finds anything that it cannot handle then it
 ;; writes a warning to this buffer.  If the variable `woman-show-log'
-;; is non-nil (by default it is `nil') then WoMan automatically
+;; is non-nil (by default it is nil) then WoMan automatically
 ;; displays this buffer.  Many WoMan warnings can be completely
 ;; ignored, because they are reporting the fact that WoMan has ignored
 ;; requests that it is correct to ignore.  In some future version this
@@ -228,8 +228,8 @@
 
 ;; Uninterpreted ?roff requests can optionally be left in the
 ;; formatted buffer to indicate precisely where they occur by
-;; resetting the variable `woman-ignore' to `nil' (by default it is
-;; `t').
+;; resetting the variable `woman-ignore' to nil (by default it is
+;; t).
 
 ;; Automatic initiation of woman decoding
 
@@ -278,7 +278,7 @@
 ;; CASE-DEPENDENCE OF FILENAMES.  By default, WoMan ignores case in
 ;; file pathnames only when it seems appropriate.  MS-Windows users
 ;; who want complete case independence should set the NTEmacs variable
-;; `w32-downcase-file-names' to `t' and use all lower case when
+;; `w32-downcase-file-names' to t and use all lower case when
 ;; setting WoMan file paths.
 
 ;; (1) INCOMPATIBLE CHANGE!  WoMan no longer uses a persistent topic
diff --git a/src/buffer.c b/src/buffer.c
index 148d077ec21..c78d08c53d2 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -6106,7 +6106,7 @@ An entry of the form POSITION indicates that point was at the buffer
 location given by the integer.  Undoing an entry of this form places
 point at POSITION.
 
-Entries with value `nil' mark undo boundaries.  The undo command treats
+Entries with value nil mark undo boundaries.  The undo command treats
 the changes between two undo boundaries as a single step to be undone.
 
 If the value of the variable is t, undo information is not recorded.  */);
diff --git a/src/font.c b/src/font.c
index 355353a4f4a..2ade45fd73a 100644
--- a/src/font.c
+++ b/src/font.c
@@ -3866,7 +3866,7 @@ required OpenType features.
   GSUB: List of OpenType GSUB feature tag symbols, or nil if none required.
   GPOS: List of OpenType GPOS feature tag symbols, or nil if none required.
 
-GSUB and GPOS may contain `nil' element.  In such a case, the font
+GSUB and GPOS may contain nil elements.  In such a case, the font
 must not have any of the remaining elements.
 
 For instance, if the VALUE is `(thai nil nil (mark))', the font must
@@ -5011,7 +5011,7 @@ build_style_table (const struct table_entry *entry, int nelement)
 static Lisp_Object Vfont_log_deferred;
 
 /* Prepend the font-related logging data in Vfont_log if it is not
-   `t'.  ACTION describes a kind of font-related action (e.g. listing,
+   t.  ACTION describes a kind of font-related action (e.g. listing,
    opening), ARG is the argument for the action, and RESULT is the
    result of the action.  */
 void
diff --git a/src/frame.c b/src/frame.c
index edf656694b7..478bb00337b 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -5152,7 +5152,7 @@ a non-nil value in your init file.  */);
 If this option is nil, setting font, menu bar, tool bar, internal
 borders, fringes or scroll bars of a specific frame may resize the frame
 in order to preserve the number of columns or lines it displays.  If
-this option is `t', no such resizing is done.  Note that the size of
+this option is t, no such resizing is done.  Note that the size of
 fullscreen and maximized frames, the height of fullheight frames and the
 width of fullwidth frames never change implicitly.
 
@@ -5168,14 +5168,14 @@ Changing any of the parameters `scroll-bar-width', `scroll-bar-height',
 window.  This means, for example, that removing vertical scroll bars on
 a frame containing several side by side windows will shrink the frame
 width by the width of one scroll bar provided this option is nil and
-keep it unchanged if this option is either `t' or a list containing
+keep it unchanged if this option is either t or a list containing
 `vertical-scroll-bars'.
 
 The default value is '(tool-bar-lines) on Lucid, Motif and Windows
 \(which means that adding/removing a tool bar does not change the frame
 height), nil on all other window systems including GTK+ (which means
 that changing any of the parameters listed above may change the size of
-the frame), and `t' otherwise (which means the frame size never changes
+the frame), and t otherwise (which means the frame size never changes
 implicitly when there's no window system support).
 
 Note that when a frame is not large enough to accommodate a change of
diff --git a/src/gnutls.c b/src/gnutls.c
index 9b8ae2bd1a8..9c2d86ecdfc 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -1181,7 +1181,7 @@ gnutls_certificate_set_verify_flags.
 instead.
 
 :verify-error is a list of symbols to express verification checks or
-`t' to do all checks.  Currently it can contain `:trustfiles' and
+t to do all checks.  Currently it can contain `:trustfiles' and
 `:hostname' to verify the certificate or the hostname respectively.
 
 :min-prime-bits is the minimum accepted number of bits the client will
diff --git a/src/keymap.c b/src/keymap.c
index d10c00489d1..e9898051dc7 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -498,7 +498,7 @@ access_keymap_1 (Lisp_Object map, Lisp_Object idx,
             if (INTEGERP (idx) && (XFASTINT (idx) & CHAR_MODIFIER_MASK) == 0)
               {
                 val = Faref (binding, idx);
-                /* `nil' has a special meaning for char-tables, so
+                /* nil has a special meaning for char-tables, so
                    we use something else to record an explicitly
                    unbound entry.  */
                 if (NILP (val))
@@ -849,7 +849,7 @@ store_in_keymap (Lisp_Object keymap, register Lisp_Object idx, Lisp_Object def)
             if (NATNUMP (idx) && !(XFASTINT (idx) & CHAR_MODIFIER_MASK))
               {
                 Faset (elt, idx,
-                       /* `nil' has a special meaning for char-tables, so
+                       /* nil has a special meaning for char-tables, so
                           we use something else to record an explicitly
                           unbound entry.  */
                        NILP (def) ? Qt : def);
diff --git a/src/nsfns.m b/src/nsfns.m
index 8a3c6ccf2b0..6a2e2ff14a4 100644
--- a/src/nsfns.m
+++ b/src/nsfns.m
@@ -749,7 +749,7 @@ ns_implicitly_set_icon_type (struct frame *f)
        chain = XCDR (chain))
     {
       elt = XCAR (chain);
-      /* special case: 't' means go by file type */
+      /* special case: t means go by file type */
       if (SYMBOLP (elt) && EQ (elt, Qt) && SSDATA (f->name)[0] == '/')
         {
           NSString *str
@@ -2836,13 +2836,13 @@ elements (all size values are in pixels).
 
 - `title-bar-height' is the height of the title bar of FRAME.
 
-- `menu-bar-external' if `t' means the menu bar is external (not
+- `menu-bar-external' if t means the menu bar is external (not
   included in the inner edges of FRAME).
 
 - `menu-bar-size' is a cons of the width and height of the menu bar of
   FRAME.
 
-- `tool-bar-external' if `t' means the tool bar is external (not
+- `tool-bar-external' if t means the tool bar is external (not
   included in the inner edges of FRAME).
 
 - `tool-bar-side' tells tells on which side the tool bar on FRAME is and
diff --git a/src/w32fns.c b/src/w32fns.c
index b9d7bd4d75b..3a6fa624056 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -7535,13 +7535,13 @@ elements (all size values are in pixels).
 
 - `title-bar-height' is the height of the title bar of FRAME.
 
-- `menu-bar-external' if `t' means the menu bar is by default external
+- `menu-bar-external' if t means the menu bar is by default external
   (not included in the inner size of FRAME).
 
 - `menu-bar-size' is a cons of the width and height of the menu bar of
   FRAME.
 
-- `tool-bar-external' if `t' means the tool bar is by default external
+- `tool-bar-external' if t means the tool bar is by default external
   (not included in the inner size of FRAME).
 
 - `tool-bar-side' tells tells on which side the tool bar on FRAME is by
diff --git a/src/xfns.c b/src/xfns.c
index bd1db1013d0..03ef8136ae2 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -4316,13 +4316,13 @@ elements (all size values are in pixels).
 
 - `title-bar-height' is the height of the title bar of FRAME.
 
-- `menu-bar-external' if `t' means the menu bar is external (not
+- `menu-bar-external' if t means the menu bar is external (not
   included in the inner edges of FRAME).
 
 - `menu-bar-size' is a cons of the width and height of the menu bar of
   FRAME.
 
-- `tool-bar-external' if `t' means the tool bar is external (not
+- `tool-bar-external' if t means the tool bar is external (not
   included in the inner edges of FRAME).
 
 - `tool-bar-side' tells tells on which side the tool bar on FRAME is and
diff --git a/test/automated/data/package/newer-versions/simple-single-1.4.el b/test/automated/data/package/newer-versions/simple-single-1.4.el
index 7d8178c05a5..7b1c00c06db 100644
--- a/test/automated/data/package/newer-versions/simple-single-1.4.el
+++ b/test/automated/data/package/newer-versions/simple-single-1.4.el
@@ -19,7 +19,7 @@
 
 (defcustom simple-single-super-sunday nil
   "How great is this?
-Default changed to `nil'."
+Default changed to nil."
   :type 'boolean
   :group 'simple-single
   :package-version "1.4")
diff --git a/test/automated/file-notify-tests.el b/test/automated/file-notify-tests.el
index 8e3a7918c80..46d287fe60d 100644
--- a/test/automated/file-notify-tests.el
+++ b/test/automated/file-notify-tests.el
@@ -72,7 +72,7 @@
 (defun file-notify--test-local-enabled ()
   "Whether local file notification is enabled.
 This is needed for local `temporary-file-directory' only, in the
-remote case we return always `t'."
+remote case we return always t."
   (or file-notify--library
       (file-remote-p temporary-file-directory)))
 
diff --git a/test/automated/package-test.el b/test/automated/package-test.el
index ed2e3cf25aa..677bfa613fc 100644
--- a/test/automated/package-test.el
+++ b/test/automated/package-test.el
@@ -124,7 +124,7 @@
           ,@(if upload-base
                 '((package-test-archive-upload-base (make-temp-file "pkg-archive-base-" t))
                   (package-archive-upload-base package-test-archive-upload-base))
-              (list (cl-gensym)))) ;; Dummy value so `let' doesn't try to bind `nil'
+              (list (cl-gensym)))) ;; Dummy value so `let' doesn't try to bind nil
      (let ((buf (get-buffer "*Packages*")))
        (when (buffer-live-p buf)
          (kill-buffer buf)))