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.

8 files changed, 16 insertions, 16 deletions

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