120 files changed, 172 insertions, 143 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index f8dc0be7ed5..e3c212924b3 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -23,6 +23,12 @@
         * macterm.c [TARGET_API_MAC_CARBON] (mac_handle_window_event):
         Don't use invisible frame as parent window for repositioning.
 
+2007-08-10  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * print.c (new_backquote_output): Rename from old_backquote_output.
+        (print): Inverse its logic (according to its name) so as to match the
+        behavior of new_backquote_flag in lread.c.
+
 2007-08-09  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
 
         * gmalloc.c (posix_memalign): New function.
@@ -41,6 +47,10 @@
         (mac_handle_window_event) [USE_MAC_TOOLBAR]: Add further workaround
         for window repositioning.
 
+2007-08-08  Glenn Morris  <rgm@gnu.org>
+
+        * Replace `iff' in doc-strings and comments.
+
 2007-08-07  Chong Yidong  <cyd@stupidchicken.com>
 
         * xdisp.c (move_it_by_lines): Remove incorrect optimization.
diff --git a/src/buffer.h b/src/buffer.h
index 65cfef4f04f..ed99dc4ffb1 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -561,7 +561,7 @@ struct buffer
   Lisp_Object filename;
   /* Dir for expanding relative file names.  */
   Lisp_Object directory;
-  /* True iff this buffer has been backed up (if you write to the
+  /* True if this buffer has been backed up (if you write to the
      visited file and it hasn't been backed up, then a backup will
      be made).  */
   /* This isn't really used by the C code, so could be deleted.  */
diff --git a/src/callproc.c b/src/callproc.c
index 1ea0dfa43a6..bf7ea43b868 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -117,7 +117,7 @@ Lisp_Object Vprocess_environment;
 Lisp_Object Qbuffer_file_type;
 #endif /* DOS_NT */
 
-/* True iff we are about to fork off a synchronous process or if we
+/* True if we are about to fork off a synchronous process or if we
    are waiting for it.  */
 int synch_process_alive;
 
diff --git a/src/casetab.c b/src/casetab.c
index bf0e022f139..952a320dda3 100644
--- a/src/casetab.c
+++ b/src/casetab.c
@@ -40,7 +40,7 @@ static void set_identity ();
 static void shuffle ();
 
 DEFUN ("case-table-p", Fcase_table_p, Scase_table_p, 1, 1, 0,
-       doc: /* Return t iff OBJECT is a case table.
+       doc: /* Return t if OBJECT is a case table.
 See `set-case-table' for more information on these data structures.  */)
      (object)
      Lisp_Object object;
diff --git a/src/category.c b/src/category.c
index 55e752045e7..7ea9b7810fa 100644
--- a/src/category.c
+++ b/src/category.c
@@ -559,7 +559,7 @@ syms_of_category ()
                doc: /* List of pair (cons) of categories to determine word boundary.
 
 Emacs treats a sequence of word constituent characters as a single
-word (i.e. finds no word boundary between them) iff they belongs to
+word (i.e. finds no word boundary between them) only if they belong to
 the same charset.  But, exceptions are allowed in the following cases.
 
 \(1) The case that characters are in different charsets is controlled
diff --git a/src/ccl.c b/src/ccl.c
index c25e67abf57..564fd4ba4fa 100644
--- a/src/ccl.c
+++ b/src/ccl.c
@@ -659,13 +659,13 @@ while (0)
 
 #define CCL_LookupIntConstTbl 0x13 /* Lookup multibyte character by
                                       integer key.  Afterwards R7 set
-                                      to 1 iff lookup succeeded.
+                                      to 1 if lookup succeeded.
                                       1:ExtendedCOMMNDRrrRRRXXXXXXXX
                                       2:ARGUMENT(Hash table ID) */
 
 #define CCL_LookupCharConstTbl 0x14 /* Lookup integer by multibyte
                                        character key.  Afterwards R7 set
-                                       to 1 iff lookup succeeded.
+                                       to 1 if lookup succeeded.
                                        1:ExtendedCOMMNDRrrRRRrrrXXXXX
                                        2:ARGUMENT(Hash table ID) */
 
diff --git a/src/charset.c b/src/charset.c
index a6ec309cbb3..1a85cd39c72 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -337,7 +337,7 @@ split_string (str, len, charset, c1, c2)
   return 0;
 }
 
-/* Return 1 iff character C has valid printable glyph.
+/* Return 1 if character C has valid printable glyph.
    Use the macro CHAR_PRINTABLE_P instead.  */
 int
 char_printable_p (c)
@@ -1102,8 +1102,8 @@ DIMENSION, CHARS, and FINAL-CHAR.  */)
   return CHARSET_SYMBOL (charset);
 }
 
-/* If GENERICP is nonzero, return nonzero iff C is a valid normal or
-   generic character.  If GENERICP is zero, return nonzero iff C is a
+/* If GENERICP is nonzero, return nonzero if C is a valid normal or
+   generic character.  If GENERICP is zero, return nonzero if C is a
    valid normal character.  Do not call this function directly,
    instead use macro CHAR_VALID_P.  */
 int
diff --git a/src/charset.h b/src/charset.h
index 984d466d97d..c20766f910b 100644
--- a/src/charset.h
+++ b/src/charset.h
@@ -413,8 +413,8 @@ extern int width_by_char_head[256];
             | ((c1) <= 0 ? 0 : (((c1) & 0x7F) << 7))))))
 
 
-/* If GENERICP is nonzero, return nonzero iff C is a valid normal or
-   generic character.  If GENERICP is zero, return nonzero iff C is a
+/* If GENERICP is nonzero, return nonzero if C is a valid normal or
+   generic character.  If GENERICP is zero, return nonzero if C is a
    valid normal character.  */
 #define CHAR_VALID_P(c, genericp)       \
   ((c) >= 0                             \
@@ -450,7 +450,7 @@ extern int width_by_char_head[256];
 #define VALID_LEADING_CODE_P(code)      \
   (! NILP (CHARSET_TABLE_ENTRY (code)))
 
-/* Return 1 iff the byte sequence at unibyte string STR (LENGTH bytes)
+/* Return 1 if the byte sequence at unibyte string STR (LENGTH bytes)
    is valid as a multibyte form.  If valid, by a side effect, BYTES is
    set to the byte length of the multibyte form.  */
 
@@ -471,7 +471,7 @@ extern int width_by_char_head[256];
                      && VALID_LEADING_CODE_P (str[1]))))))))
 
 
-/* Return 1 iff the byte sequence at multibyte string STR is valid as
+/* Return 1 if the byte sequence at multibyte string STR is valid as
    a unibyte form.  By a side effect, BYTES is set to the byte length
    of one character at STR.  */
 
@@ -499,7 +499,7 @@ extern int width_by_char_head[256];
          c1 = CHAR_FIELD3 (c),                                              \
          c2 = -1)))
 
-/* Return 1 iff character C has valid printable glyph.  */
+/* Return 1 if character C has valid printable glyph.  */
 #define CHAR_PRINTABLE_P(c) (ASCII_BYTE_P (c) || char_printable_p (c))
 
 /* The charset of the character at STR is stored in CHARSET, and the
diff --git a/src/coding.h b/src/coding.h
index 9906e66af6c..2efcd4f47e2 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -263,7 +263,7 @@ enum coding_type
                                      eol-type is not consistent
                                      through the file.  */
 
-/* 1 iff composing.  */
+/* 1 if composing.  */
 #define COMPOSING_P(coding) ((int) coding->composing > (int) COMPOSITION_NO)
 
 #define COMPOSITION_DATA_SIZE 4080
@@ -372,7 +372,7 @@ struct coding_system
   /* The current status of composition handling.  */
   int composing;
 
-  /* 1 iff the next character is a composition rule.  */
+  /* 1 if the next character is a composition rule.  */
   int composition_rule_follows;
 
   /* Information of compositions are stored here on decoding and set
diff --git a/src/composite.h b/src/composite.h
index 5dc8dde62e2..ba8f8c84104 100644
--- a/src/composite.h
+++ b/src/composite.h
@@ -56,7 +56,7 @@ enum composition_method {
 /* Temporary variable used only in the following macros.  */
 extern Lisp_Object composition_temp;
 
-/* Return 1 iff the composition is already registered.  */
+/* Return 1 if the composition is already registered.  */
 #define COMPOSITION_REGISTERD_P(prop) INTEGERP (XCAR (prop))
 
 /* Return ID number of the already registered composition.  */
@@ -91,7 +91,7 @@ extern Lisp_Object composition_temp;
           ? COMPOSITION_WITH_ALTCHARS                                   \
           : COMPOSITION_WITH_RULE_ALTCHARS))))
 
-/* Return 1 iff the composition is valid.  It is valid if length of
+/* Return 1 if the composition is valid.  It is valid if length of
    the composition equals to (END - START).  */
 #define COMPOSITION_VALID_P(start, end, prop)                   \
   (CONSP (prop)                                                 \
diff --git a/src/dired.c b/src/dired.c
index 22283b66ea0..1fb5387268a 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -916,7 +916,7 @@ Elements of the attribute list are:
  7. Size in bytes.
   This is a floating point number if the size is too large for an integer.
  8. File modes, as a string of ten letters or dashes as in ls -l.
- 9. t iff file's gid would change if file were deleted and recreated.
+ 9. t if file's gid would change if file were deleted and recreated.
 10. inode number.  If inode number is larger than the Emacs integer,
   this is a cons cell containing two integers: first the high part,
   then the low 16 bits.
diff --git a/src/editfns.c b/src/editfns.c
index 7bb74958c2c..dac7eb83af2 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -3514,7 +3514,7 @@ usage: (format STRING &rest OBJECTS)  */)
            precision    ::= '.' [0-9]*
 
            If a field-width is specified, it specifies to which width
-           the output should be padded with blanks, iff the output
+           the output should be padded with blanks, if the output
            string is shorter than field-width.
 
            If precision is specified, it specifies the number of
diff --git a/src/eval.c b/src/eval.c
index 78316eb1a3c..6ce64bc4d8c 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1783,7 +1783,7 @@ signal_error (s, arg)
 }
 
 
-/* Return nonzero iff LIST is a non-nil atom or
+/* Return nonzero if LIST is a non-nil atom or
    a list containing one of CONDITIONS.  */
 
 static int
diff --git a/src/fileio.c b/src/fileio.c
index 195e76db658..45eb7d29f91 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -5256,7 +5256,7 @@ This does code conversion according to the value of
  * if we do writes that don't end with a carriage return. Furthermore
  * it cannot handle writes of more then 16K. The modified
  * version of "sys_write" in SYSDEP.C (see comment there) copes with
- * this EXCEPT for the last record (iff it doesn't end with a carriage
+ * this EXCEPT for the last record (if it doesn't end with a carriage
  * return). This implies that if your buffer doesn't end with a carriage
  * return, you get one free... tough. However it also means that if
  * we make two calls to sys_write (a la the following code) you can
diff --git a/src/fontset.c b/src/fontset.c
index 97f86faaff9..9056e2da6ec 100644
--- a/src/fontset.c
+++ b/src/fontset.c
@@ -500,7 +500,7 @@ free_face_fontset (f, face)
 }
 
 
-/* Return 1 iff FACE is suitable for displaying character C.
+/* Return 1 if FACE is suitable for displaying character C.
    Otherwise return 0.  Called from the macro FACE_SUITABLE_FOR_CHAR_P
    when C is not a single byte character..  */
 
diff --git a/src/fontset.h b/src/fontset.h
index 5b5c5cbcfaa..c8bd1e36eab 100644
--- a/src/fontset.h
+++ b/src/fontset.h
@@ -66,7 +66,7 @@ struct font_info
   /* Average width of glyphs in the font.  */
   int average_width;
 
-  /* 1 iff `vertical-centering-font-regexp' matches this font name.
+  /* 1 if `vertical-centering-font-regexp' matches this font name.
      In this case, we render characters at vartical center positions
      of lines.  */
   int vertical_centering;
diff --git a/src/getloadavg.c b/src/getloadavg.c
index f40149a8c47..6d66cbfd8a1 100644
--- a/src/getloadavg.c
+++ b/src/getloadavg.c
@@ -484,7 +484,7 @@ static struct dg_sys_info_load_info load_info;	/* what-a-mouthful! */
 #if !defined(HAVE_LIBKSTAT) && defined(LOAD_AVE_TYPE)
 /* File descriptor open to /dev/kmem or VMS load ave driver.  */
 static int channel;
-/* Nonzero iff channel is valid.  */
+/* Nonzero if channel is valid.  */
 static int getloadavg_initialized;
 /* Offset in kmem to seek to read load average, or 0 means invalid.  */
 static long offset;
diff --git a/src/indent.c b/src/indent.c
index 905cf7559a7..b3c1d0cf81a 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -116,7 +116,7 @@ character_width (c, dp)
     return 0;
 }
 
-/* Return true iff the display table DISPTAB specifies the same widths
+/* Return true if the display table DISPTAB specifies the same widths
    for characters as WIDTHTAB.  We use this to decide when to
    invalidate the buffer's width_run_cache.  */
 
diff --git a/src/indent.h b/src/indent.h
index 2d3c158b069..2e873769603 100644
--- a/src/indent.h
+++ b/src/indent.h
@@ -61,7 +61,7 @@ extern int last_known_column_point;
 
 /* Functions for dealing with the column cache.  */
 
-/* Return true iff the display table DISPTAB specifies the same widths
+/* Return true if the display table DISPTAB specifies the same widths
    for characters as WIDTHTAB.  We use this to decide when to
    invalidate the buffer's column_cache.  */
 int disptab_matches_widthtab P_ ((struct Lisp_Char_Table *disptab,
diff --git a/src/intervals.c b/src/intervals.c
index 89f99a052b9..a695976b8b7 100644
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -2200,7 +2200,7 @@ set_point_both (buffer, charpos, bytepos)
 
   temp_set_point_both (buffer, charpos, bytepos);
 
-  /* We run point-left and point-entered hooks here, iff the
+  /* We run point-left and point-entered hooks here, if the
      two intervals are not equivalent.  These hooks take
      (old_point, new_point) as arguments.  */
   if (NILP (Vinhibit_point_motion_hooks)
diff --git a/src/keyboard.c b/src/keyboard.c
index b096424a615..c542d291b46 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -500,7 +500,7 @@ static struct input_event * volatile kbd_store_ptr;
 /* The above pair of variables forms a "queue empty" flag.  When we
    enqueue a non-hook event, we increment kbd_store_ptr.  When we
    dequeue a non-hook event, we increment kbd_fetch_ptr.  We say that
-   there is input available iff the two pointers are not equal.
+   there is input available if the two pointers are not equal.
 
    Why not just have a flag set and cleared by the enqueuing and
    dequeuing functions?  Such a flag could be screwed up by interrupts
@@ -3590,7 +3590,7 @@ restore_getcjmp (temp)
    kbd_buffer_store_event places events in kbd_buffer, and
    kbd_buffer_get_event retrieves them.  */
 
-/* Return true iff there are any events in the queue that read-char
+/* Return true if there are any events in the queue that read-char
    would return.  If this returns false, a read-char would block.  */
 static int
 readable_events (flags)
diff --git a/src/keyboard.h b/src/keyboard.h
index e24f9a133ae..15e55ad4e67 100644
--- a/src/keyboard.h
+++ b/src/keyboard.h
@@ -240,7 +240,7 @@ extern Lisp_Object item_properties;
 
 /* Macros for dealing with lispy events.  */
 
-/* True iff EVENT has data fields describing it (i.e. a mouse click).  */
+/* True if EVENT has data fields describing it (i.e. a mouse click).  */
 #define EVENT_HAS_PARAMETERS(event) (CONSP (event))
 
 /* Extract the head from an event.
diff --git a/src/keymap.c b/src/keymap.c
index c9817199a4f..2c760050c1d 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -4074,7 +4074,7 @@ don't alter it yourself.  */);
   DEFVAR_LISP ("minor-mode-map-alist", &Vminor_mode_map_alist,
                doc: /* Alist of keymaps to use for minor modes.
 Each element looks like (VARIABLE . KEYMAP); KEYMAP is used to read
-key sequences and look up bindings iff VARIABLE's value is non-nil.
+key sequences and look up bindings if VARIABLE's value is non-nil.
 If two active keymaps bind the same key, the keymap appearing earlier
 in the list takes precedence.  */);
   Vminor_mode_map_alist = Qnil;
diff --git a/src/lisp.h b/src/lisp.h
index d86fdc0e915..c5d9724e96c 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1444,7 +1444,7 @@ typedef unsigned char UCHAR;
 #define GLYPH_CHAR(f, g) (FAST_GLYPH_CHAR (g))
 #define GLYPH_FACE(f, g) (FAST_GLYPH_FACE (g))
 
-/* Return 1 iff GLYPH contains valid character code.  */
+/* Return 1 if GLYPH contains valid character code.  */
 #define GLYPH_CHAR_VALID_P(glyph) CHAR_VALID_P (FAST_GLYPH_CHAR (glyph), 1)
 
 /* The ID of the mode line highlighting face.  */
@@ -1591,7 +1591,7 @@ typedef unsigned char UCHAR;
    "dead", which is what we want; this is an argument-checking macro, and
    the user should never get access to interior windows.
 
-   A window of any sort, leaf or interior, is dead iff the buffer,
+   A window of any sort, leaf or interior, is dead if the buffer,
    vchild, and hchild members are all nil.  */
 
 #define CHECK_LIVE_WINDOW(x) \
diff --git a/src/lread.c b/src/lread.c
index 20587c6759e..282bf1d6b07 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -93,7 +93,7 @@ Lisp_Object Qfile_truename, Qdo_after_load_evaluation; /* ACM 2006/5/16 */
 extern Lisp_Object Qevent_symbol_element_mask;
 extern Lisp_Object Qfile_exists_p;
 
-/* non-zero iff inside `load' */
+/* non-zero if inside `load' */
 int load_in_progress;
 
 /* Directory in which the sources were found.  */
@@ -1126,7 +1126,7 @@ in which case file-name-handlers are ignored.  */)
    On success, returns a file descriptor.  On failure, returns -1.
 
    SUFFIXES is a list of strings containing possible suffixes.
-   The empty suffix is automatically added iff the list is empty.
+   The empty suffix is automatically added if the list is empty.
 
    PREDICATE non-nil means don't open the files,
    just look for one that satisfies the predicate.  In this case,
@@ -4077,7 +4077,7 @@ customize `jka-compr-load-suffixes' rather than the present variable.  */);
   Vload_file_rep_suffixes = Fcons (empty_unibyte_string, Qnil);
 
   DEFVAR_BOOL ("load-in-progress", &load_in_progress,
-               doc: /* Non-nil iff inside of `load'.  */);
+               doc: /* Non-nil if inside of `load'.  */);
 
   DEFVAR_LISP ("after-load-alist", &Vafter_load_alist,
                doc: /* An alist of expressions to be evalled when particular files are loaded.
diff --git a/src/m/7300.h b/src/m/7300.h
index b590593abc8..6e439a829cc 100644
--- a/src/m/7300.h
+++ b/src/m/7300.h
@@ -30,7 +30,7 @@ Boston, MA 02110-1301, USA.  */
 /* # define SHORTNAMES */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/acorn.h b/src/m/acorn.h
index 7fa5991e28b..148d46454ab 100644
--- a/src/m/acorn.h
+++ b/src/m/acorn.h
@@ -21,7 +21,7 @@ Boston, MA 02110-1301, USA.  */
 
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/alliant-2800.h b/src/m/alliant-2800.h
index 3d65f9d1f12..405267afb2b 100644
--- a/src/m/alliant-2800.h
+++ b/src/m/alliant-2800.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/alliant.h b/src/m/alliant.h
index b871d4a2385..7cad4bfb0c1 100644
--- a/src/m/alliant.h
+++ b/src/m/alliant.h
@@ -26,7 +26,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/alpha.h b/src/m/alpha.h
index 84e74d581d1..5e46a05ab68 100644
--- a/src/m/alpha.h
+++ b/src/m/alpha.h
@@ -35,7 +35,7 @@ NOTE-END
                                    on OSF 4/5  -- fx.  */
 #endif
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/altos.h b/src/m/altos.h
index 8a1cb138345..0f4bb9b810f 100644
--- a/src/m/altos.h
+++ b/src/m/altos.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/amdahl.h b/src/m/amdahl.h
index 3d9ee17e91f..486e2925a55 100644
--- a/src/m/amdahl.h
+++ b/src/m/amdahl.h
@@ -31,7 +31,7 @@ This file works with the Amdahl uts native C compiler. The 5.2u370
 compiler is so brain damaged that it is not even worth trying to use it.
 */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/amdx86-64.h b/src/m/amdx86-64.h
index fbd53a955a2..681be8b0647 100644
--- a/src/m/amdx86-64.h
+++ b/src/m/amdx86-64.h
@@ -26,7 +26,7 @@ Boston, MA 02110-1301, USA.  */
 #define BITS_PER_LONG           64
 #define BITS_PER_EMACS_INT      64
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/apollo.h b/src/m/apollo.h
index b769c24c294..2eac3098db9 100644
--- a/src/m/apollo.h
+++ b/src/m/apollo.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/arm.h b/src/m/arm.h
index b1df83f9b70..697179723f7 100644
--- a/src/m/arm.h
+++ b/src/m/arm.h
@@ -21,7 +21,7 @@ Boston, MA 02110-1301, USA.  */
 
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/att3b.h b/src/m/att3b.h
index 3344aabc2a9..8e9a589bcd2 100644
--- a/src/m/att3b.h
+++ b/src/m/att3b.h
@@ -26,7 +26,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/aviion.h b/src/m/aviion.h
index 7f3f7f253d5..832feb79a00 100644
--- a/src/m/aviion.h
+++ b/src/m/aviion.h
@@ -20,7 +20,7 @@ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/celerity.h b/src/m/celerity.h
index 76f1e1729b3..556c2765883 100644
--- a/src/m/celerity.h
+++ b/src/m/celerity.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/clipper.h b/src/m/clipper.h
index de99ba97eb5..c0006f48eab 100644
--- a/src/m/clipper.h
+++ b/src/m/clipper.h
@@ -20,7 +20,7 @@ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/cnvrgnt.h b/src/m/cnvrgnt.h
index f64fc86b08b..22478a273b6 100644
--- a/src/m/cnvrgnt.h
+++ b/src/m/cnvrgnt.h
@@ -20,7 +20,7 @@ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/convex.h b/src/m/convex.h
index 7f90d22117c..c8f447cf2fa 100644
--- a/src/m/convex.h
+++ b/src/m/convex.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/cydra5.h b/src/m/cydra5.h
index 2361fb4b589..4c95f226371 100644
--- a/src/m/cydra5.h
+++ b/src/m/cydra5.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/delta88k.h b/src/m/delta88k.h
index c767e1db1ca..b5d0c8f190b 100644
--- a/src/m/delta88k.h
+++ b/src/m/delta88k.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/dpx2.h b/src/m/dpx2.h
index 1c1d146a08a..b39ef93ee34 100644
--- a/src/m/dpx2.h
+++ b/src/m/dpx2.h
@@ -32,7 +32,7 @@ Boston, MA 02110-1301, USA.  */
 /* #define ncl_el       /* DPX/2 210,220 etc */
 /* #define ncl_mr 1     /* DPX/2 320,340 (and 360,380 ?) */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/dual.h b/src/m/dual.h
index 4fda7a8a96c..d287f9502d2 100644
--- a/src/m/dual.h
+++ b/src/m/dual.h
@@ -35,7 +35,7 @@ Dual running Uniplus (-machine=dual -opsystem=unipl5-2)
 NOTE-END */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/elxsi.h b/src/m/elxsi.h
index 81689e66e52..07a00bbf714 100644
--- a/src/m/elxsi.h
+++ b/src/m/elxsi.h
@@ -27,7 +27,7 @@ Boston, MA 02110-1301, USA.  */
 /* This file was modified by Matt Crawford <matt@tank.uchicago.edu>
    to work under Elxsi's 12.0 release of BSD unix. */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/gould.h b/src/m/gould.h
index c31f50249e7..cd16e09b785 100644
--- a/src/m/gould.h
+++ b/src/m/gould.h
@@ -49,7 +49,7 @@ Gould Power Node (-machine=gould -opsystem=bsd4-2 or bsd4-3)
   A site running a pre-release of 2.1 should #define RELEASE2_1 in config.h.
 NOTE-END */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/hp800.h b/src/m/hp800.h
index d54690104b5..83465052478 100644
--- a/src/m/hp800.h
+++ b/src/m/hp800.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="hpux"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/hp9000s300.h b/src/m/hp9000s300.h
index 3718bb3f3ae..9a27065f866 100644
--- a/src/m/hp9000s300.h
+++ b/src/m/hp9000s300.h
@@ -59,7 +59,7 @@ NOTE-END */
 
 /* #define HPUX_5 */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/i860.h b/src/m/i860.h
index 1255f2f1576..6d79c5c8d38 100644
--- a/src/m/i860.h
+++ b/src/m/i860.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="<name of system .h file here, without the s- or .h>"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/ia64.h b/src/m/ia64.h
index b6fea6b8fd7..8f7fed8d69e 100644
--- a/src/m/ia64.h
+++ b/src/m/ia64.h
@@ -23,7 +23,7 @@ Boston, MA 02110-1301, USA.  */
 #define BITS_PER_LONG           64
 #define BITS_PER_EMACS_INT      64
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/ibm370aix.h b/src/m/ibm370aix.h
index f632a30780b..0195ec141ab 100644
--- a/src/m/ibm370aix.h
+++ b/src/m/ibm370aix.h
@@ -30,7 +30,7 @@ Boston, MA 02110-1301, USA.  */
 #undef INTEL386
 #undef aix386
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/ibmps2-aix.h b/src/m/ibmps2-aix.h
index 8882052b006..8c975b81bb9 100644
--- a/src/m/ibmps2-aix.h
+++ b/src/m/ibmps2-aix.h
@@ -30,7 +30,7 @@ NOTE-START
   work with certain new X window managers, and may be suboptimal.
 NOTE-END */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/ibmrs6000.h b/src/m/ibmrs6000.h
index 2a298e7f760..d542c07ad0a 100644
--- a/src/m/ibmrs6000.h
+++ b/src/m/ibmrs6000.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="aix3-1"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #ifdef USG5_4
diff --git a/src/m/ibmrt-aix.h b/src/m/ibmrt-aix.h
index d24e99fe6d6..57a9dbc4df1 100644
--- a/src/m/ibmrt-aix.h
+++ b/src/m/ibmrt-aix.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/ibmrt.h b/src/m/ibmrt.h
index 55cbfd88371..ca32db94518 100644
--- a/src/m/ibmrt.h
+++ b/src/m/ibmrt.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/ibms390.h b/src/m/ibms390.h
index aece0f7599e..1c7165e04c0 100644
--- a/src/m/ibms390.h
+++ b/src/m/ibms390.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="<name of system .h file here, without the s- or .h>"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/ibms390x.h b/src/m/ibms390x.h
index fb1f210c634..64ede365d0c 100644
--- a/src/m/ibms390x.h
+++ b/src/m/ibms390x.h
@@ -36,7 +36,7 @@ NOTE-END */
 #define BITS_PER_LONG 64
 #define BITS_PER_EMACS_INT 64
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/intel386.h b/src/m/intel386.h
index 7c6c2106d17..22205ed762c 100644
--- a/src/m/intel386.h
+++ b/src/m/intel386.h
@@ -50,7 +50,7 @@ Prime EXL (-machine=intel386 -opsystem=usg5-3)
   Minor changes merged in 19.1.
 NOTE-END */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/iris4d.h b/src/m/iris4d.h
index d918c25aede..4c15131e595 100644
--- a/src/m/iris4d.h
+++ b/src/m/iris4d.h
@@ -20,7 +20,7 @@ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/irist.h b/src/m/irist.h
index 0b33bd964aa..c0d55f96d0f 100644
--- a/src/m/irist.h
+++ b/src/m/irist.h
@@ -58,7 +58,7 @@ NOTE-END */
   (copy-file), it would say that it is non-critical...
 #endif /* 0 */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/isi-ov.h b/src/m/isi-ov.h
index 7e25ed9d277..6706ee9981b 100644
--- a/src/m/isi-ov.h
+++ b/src/m/isi-ov.h
@@ -30,7 +30,7 @@ NOTE-END */
 
 #define ISI68K
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/m68k.h b/src/m/m68k.h
index c771e863711..4c600a44d8c 100644
--- a/src/m/m68k.h
+++ b/src/m/m68k.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
  the size of various data types.  */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/macppc.h b/src/m/macppc.h
index cc4afe31519..d4561c0289f 100644
--- a/src/m/macppc.h
+++ b/src/m/macppc.h
@@ -19,7 +19,7 @@ along with GNU Emacs; see the file COPYING.  If not, write to
 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/masscomp.h b/src/m/masscomp.h
index ac753de1537..4e95c268860 100644
--- a/src/m/masscomp.h
+++ b/src/m/masscomp.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="rtu"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/mega68.h b/src/m/mega68.h
index 6d991ba06a2..0d22b572fc5 100644
--- a/src/m/mega68.h
+++ b/src/m/mega68.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/mg1.h b/src/m/mg1.h
index 647544e21e4..515e9e23a96 100644
--- a/src/m/mg1.h
+++ b/src/m/mg1.h
@@ -34,7 +34,7 @@ own configuration files, please let the Free Software Foundation in on
 your work; we'd like to distribute this information.
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/mips-siemens.h b/src/m/mips-siemens.h
index d90a651d361..53366a1332e 100644
--- a/src/m/mips-siemens.h
+++ b/src/m/mips-siemens.h
@@ -36,7 +36,7 @@ This is the m- file for SNI RM*00 machines. Use s- sinix5-4.h file!
 With this the file mips-siemens.h is obsolete.
 NOTE-END  */
 
-/* Define BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define BIG_ENDIAN
diff --git a/src/m/mips.h b/src/m/mips.h
index b18324fb8b7..6c039c5e14c 100644
--- a/src/m/mips.h
+++ b/src/m/mips.h
@@ -29,7 +29,7 @@ Use mips4.h for RISCOS version 4; use s-bsd4-3.h with the BSD world.
 Note that the proper m file for the Decstation is pmax.h.
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #if ! (defined (__MIPSEL__) || defined (MIPSEL) || defined (_MIPSEL))
diff --git a/src/m/news.h b/src/m/news.h
index 419015dd150..084c5abb92c 100644
--- a/src/m/news.h
+++ b/src/m/news.h
@@ -34,7 +34,7 @@ NOTE-END  */
 #define m68000
 #endif
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/next.h b/src/m/next.h
index ef92607d957..bca8ac39d47 100644
--- a/src/m/next.h
+++ b/src/m/next.h
@@ -26,7 +26,7 @@ Boston, MA 02110-1301, USA.  */
 #define NeXT
 #endif
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 /* Let the compiler tell us.  */
diff --git a/src/m/ns16000.h b/src/m/ns16000.h
index c64bfa32482..6feddd97610 100644
--- a/src/m/ns16000.h
+++ b/src/m/ns16000.h
@@ -30,7 +30,7 @@ For a Tektronix 16000 box (a 6130, perhaps?), use `-opsystem=bsd4-2'.
 Use `-machine=ns16000' for both.
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/ns32000.h b/src/m/ns32000.h
index 0b776115ca8..b6484b4b219 100644
--- a/src/m/ns32000.h
+++ b/src/m/ns32000.h
@@ -25,7 +25,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/nu.h b/src/m/nu.h
index 347606a6c01..279d14ff915 100644
--- a/src/m/nu.h
+++ b/src/m/nu.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/orion.h b/src/m/orion.h
index 36a74b3cc3b..cc3a7e395fc 100644
--- a/src/m/orion.h
+++ b/src/m/orion.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/orion105.h b/src/m/orion105.h
index 73408ed1b2f..fabcf67e2a9 100644
--- a/src/m/orion105.h
+++ b/src/m/orion105.h
@@ -25,7 +25,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/pfa50.h b/src/m/pfa50.h
index 8f1f146000e..5f98dc993c7 100644
--- a/src/m/pfa50.h
+++ b/src/m/pfa50.h
@@ -20,7 +20,7 @@ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/plexus.h b/src/m/plexus.h
index 4a4e6a32f7f..51961977904 100644
--- a/src/m/plexus.h
+++ b/src/m/plexus.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/powermac.h b/src/m/powermac.h
index 729bbb0358b..2dde47bd6cf 100644
--- a/src/m/powermac.h
+++ b/src/m/powermac.h
@@ -23,7 +23,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="darwin"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/powerpcle.h b/src/m/powerpcle.h
index 403d6986bf8..5be26e93b17 100644
--- a/src/m/powerpcle.h
+++ b/src/m/powerpcle.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    USUAL-OPSYS="Solaris2.5.1 Windows/NT AIX 4.1.2"
 */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/pyramid.h b/src/m/pyramid.h
index 9ee3fefe387..1b834c60ba0 100644
--- a/src/m/pyramid.h
+++ b/src/m/pyramid.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/sequent.h b/src/m/sequent.h
index be5d3f19bd1..3c06d854b41 100644
--- a/src/m/sequent.h
+++ b/src/m/sequent.h
@@ -31,7 +31,7 @@ NOTE-END */
 /* NOTE: this file works for DYNIX release 2.0
           (not tested on 1.3) on NS32000's */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/sh3el.h b/src/m/sh3el.h
index 5851ade1523..eefcccea6de 100644
--- a/src/m/sh3el.h
+++ b/src/m/sh3el.h
@@ -23,7 +23,7 @@ Boston, MA 02111-1307, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="<name of system .h file here, without the s- or .h>"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/sparc.h b/src/m/sparc.h
index f59c2c2b969..8df81ee91aa 100644
--- a/src/m/sparc.h
+++ b/src/m/sparc.h
@@ -28,7 +28,7 @@ Use -opsystem=sunos4 for operating system version 4, and
 -opsystem=bsd4-2 for earlier versions.
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/sps7.h b/src/m/sps7.h
index 68acf2c6c52..67fc60c1b6a 100644
--- a/src/m/sps7.h
+++ b/src/m/sps7.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/sr2k.h b/src/m/sr2k.h
index ba4a9a905ab..6c17795e058 100644
--- a/src/m/sr2k.h
+++ b/src/m/sr2k.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="hpux"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/stride.h b/src/m/stride.h
index cb0380024a1..d846a6c9843 100644
--- a/src/m/stride.h
+++ b/src/m/stride.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/sun1.h b/src/m/sun1.h
index fda451a9310..03cb4e803ff 100644
--- a/src/m/sun1.h
+++ b/src/m/sun1.h
@@ -40,7 +40,7 @@ Sun 1, 2 and 3 (-machine=sun1, -machine=sun2, -machine=sun3;
   problems caused by bugs in the "export" version of SunOS 4.
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/sun2.h b/src/m/sun2.h
index 00b7ae97c4d..e764ded3ce7 100644
--- a/src/m/sun2.h
+++ b/src/m/sun2.h
@@ -42,7 +42,7 @@ Sun 1, 2 and 3 (-machine=sun1, -machine=sun2, -machine=sun3;
   problems caused by bugs in the "export" version of SunOS 4.
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/tad68k.h b/src/m/tad68k.h
index 5e982a314ab..c8be8763fb5 100644
--- a/src/m/tad68k.h
+++ b/src/m/tad68k.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/tahoe.h b/src/m/tahoe.h
index 8fe41cd4109..9b9271577fc 100644
--- a/src/m/tahoe.h
+++ b/src/m/tahoe.h
@@ -29,7 +29,7 @@ Use -opsystem=bsd4-2 or -opsystem=bsd4-3, depending on the version of
 Berkeley you are running.
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/targon31.h b/src/m/targon31.h
index 0c657e0ea5d..39e995b076d 100644
--- a/src/m/targon31.h
+++ b/src/m/targon31.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/tek4300.h b/src/m/tek4300.h
index be43210212a..6498238461d 100644
--- a/src/m/tek4300.h
+++ b/src/m/tek4300.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="bsd4-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/tekxd88.h b/src/m/tekxd88.h
index 1d46bb9bb55..f351229292f 100644
--- a/src/m/tekxd88.h
+++ b/src/m/tekxd88.h
@@ -22,7 +22,7 @@ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301, USA.  */
 
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/template.h b/src/m/template.h
index fccc5b0901c..b893ba23df2 100644
--- a/src/m/template.h
+++ b/src/m/template.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="<name of system .h file here, without the s- or .h>"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/tower32.h b/src/m/tower32.h
index 0ce623b7f37..01daada2423 100644
--- a/src/m/tower32.h
+++ b/src/m/tower32.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/tower32v3.h b/src/m/tower32v3.h
index 226c0e2640a..ff209edab41 100644
--- a/src/m/tower32v3.h
+++ b/src/m/tower32v3.h
@@ -25,7 +25,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/ustation.h b/src/m/ustation.h
index f88cdc5ee63..0ac833c28da 100644
--- a/src/m/ustation.h
+++ b/src/m/ustation.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-3"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/vax.h b/src/m/vax.h
index 80844ba3ba6..82695074424 100644
--- a/src/m/vax.h
+++ b/src/m/vax.h
@@ -52,7 +52,7 @@ Vax running VMS (-opsystem=vms)
 
 NOTE-END  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #undef WORDS_BIG_ENDIAN
diff --git a/src/m/wicat.h b/src/m/wicat.h
index 67409844666..3ac7b530739 100644
--- a/src/m/wicat.h
+++ b/src/m/wicat.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/m/windowsnt.h b/src/m/windowsnt.h
index f1efe64a4f5..ddad551c772 100644
--- a/src/m/windowsnt.h
+++ b/src/m/windowsnt.h
@@ -24,7 +24,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="<name of system .h file here, without the s- or .h>"  */
 
-/* Define BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 /* #define BIG_ENDIAN */
diff --git a/src/m/xps100.h b/src/m/xps100.h
index 691f5fedbd6..3b378319ceb 100644
--- a/src/m/xps100.h
+++ b/src/m/xps100.h
@@ -26,7 +26,7 @@ Boston, MA 02110-1301, USA.  */
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
-/* Define WORDS_BIG_ENDIAN iff lowest-numbered byte in a word
+/* Define WORDS_BIG_ENDIAN if lowest-numbered byte in a word
    is the most significant byte.  */
 
 #define WORDS_BIG_ENDIAN
diff --git a/src/macterm.c b/src/macterm.c
index 092b7488a5d..9655b09c819 100644
--- a/src/macterm.c
+++ b/src/macterm.c
@@ -12143,7 +12143,7 @@ XTread_socket (sd, expected, hold_quit)
                           /* Window will be selected only when it is
                              not selected now and last mouse movement
                              event was not in it.  Minibuffer window
-                             will be selected iff it is active.  */
+                             will be selected only when it is active.  */
                           if (WINDOWP (window)
                               && !EQ (window, last_window)
                               && !EQ (window, selected_window))
diff --git a/src/macterm.h b/src/macterm.h
index 2dc13665f67..8a85e714ab5 100644
--- a/src/macterm.h
+++ b/src/macterm.h
@@ -150,7 +150,7 @@ struct mac_display_info
   char *mac_id_name;
 
   /* The number of fonts actually stored in the font table.
-     font_table[n] is used and valid iff 0 <= n < n_fonts.  0 <=
+     font_table[n] is used and valid if 0 <= n < n_fonts.  0 <=
      n_fonts <= font_table_size and font_table[i].name != 0.  */
   int n_fonts;
 
diff --git a/src/msdos.c b/src/msdos.c
index 59854268e14..ef65597f7e7 100644
--- a/src/msdos.c
+++ b/src/msdos.c
@@ -3231,7 +3231,7 @@ dos_rawgetc ()
            `dos_get_modifiers', they might have already released the
            Alt key, and Emacs gets just `x', which is BAD.
            However, for keys with the `Map' property set, the ASCII
-           code returns zero iff Alt is pressed.  So, when we DON'T
+           code returns zero only if Alt is pressed.  So, when we DON'T
            have to support international_keyboard, we don't have to
            distinguish between the left and  right Alt keys, and we
            can set the META modifier for any keys with the `Map'
diff --git a/src/print.c b/src/print.c
index f7060024f32..cae80d1acfe 100644
--- a/src/print.c
+++ b/src/print.c
@@ -93,8 +93,8 @@ Lisp_Object Vfloat_output_format, Qfloat_output_format;
 /* Avoid actual stack overflow in print.  */
 int print_depth;
 
-/* Nonzero if inside outputting backquote in old style.  */
-int old_backquote_output;
+/* Level of nesting inside outputting backquote in new style.  */
+int new_backquote_output;
 
 /* Detect most circularities to print finite output.  */
 #define PRINT_CIRCLE 200
@@ -1291,7 +1291,7 @@ print (obj, printcharfun, escapeflag)
      register Lisp_Object printcharfun;
      int escapeflag;
 {
-  old_backquote_output = 0;
+  new_backquote_output = 0;
 
   /* Reset print_number_index and Vprint_number_table only when
      the variable Vprint_continuous_numbering is nil.  Otherwise,
@@ -1756,14 +1756,24 @@ print_object (obj, printcharfun, escapeflag)
           print_object (XCAR (XCDR (obj)), printcharfun, escapeflag);
         }
       else if (print_quoted && CONSP (XCDR (obj)) && NILP (XCDR (XCDR (obj)))
-               && ! old_backquote_output
+               && ((EQ (XCAR (obj), Qbackquote))))
+        {
+          print_object (XCAR (obj), printcharfun, 0);
+          new_backquote_output++;
+          print_object (XCAR (XCDR (obj)), printcharfun, escapeflag);
+          new_backquote_output--;
+        }
+      else if (print_quoted && CONSP (XCDR (obj)) && NILP (XCDR (XCDR (obj)))
+               && new_backquote_output
                && ((EQ (XCAR (obj), Qbackquote)
                     || EQ (XCAR (obj), Qcomma)
                     || EQ (XCAR (obj), Qcomma_at)
                     || EQ (XCAR (obj), Qcomma_dot))))
         {
           print_object (XCAR (obj), printcharfun, 0);
+          new_backquote_output--;
           print_object (XCAR (XCDR (obj)), printcharfun, escapeflag);
+          new_backquote_output++;
         }
       else
         {
@@ -1783,9 +1793,7 @@ print_object (obj, printcharfun, escapeflag)
               print_object (Qbackquote, printcharfun, 0);
               PRINTCHAR (' ');
 
-              ++old_backquote_output;
               print_object (XCAR (XCDR (tem)), printcharfun, 0);
-              --old_backquote_output;
               PRINTCHAR (')');
 
               obj = XCDR (obj);
diff --git a/src/process.c b/src/process.c
index 08358539a6c..4515b7a2c86 100644
--- a/src/process.c
+++ b/src/process.c
@@ -2780,7 +2780,7 @@ The stopped state is cleared by `continue-process' and set by
 
 :filter-multibyte BOOL -- If BOOL is non-nil, strings given to the
 process filter are multibyte, otherwise they are unibyte.
-If this keyword is not specified, the strings are multibyte iff
+If this keyword is not specified, the strings are multibyte if
 `default-enable-multibyte-characters' is non-nil.
 
 :sentinel SENTINEL -- Install SENTINEL as the process sentinel.
@@ -3917,7 +3917,7 @@ it specifies a fractional number of seconds to wait.
 If optional fourth arg JUST-THIS-ONE is non-nil, only accept output
 from PROCESS, suspending reading output from other processes.
 If JUST-THIS-ONE is an integer, don't run any timers either.
-Return non-nil iff we received any output before the timeout expired.  */)
+Return non-nil if we received any output before the timeout expired.  */)
      (process, seconds, millisec, just_this_one)
      register Lisp_Object process, seconds, millisec, just_this_one;
 {
@@ -4249,16 +4249,16 @@ select_wrapper (n, rfd, wfd, xfd, tmo)
      (and gobble terminal input into the buffer if any arrives).
 
    If WAIT_PROC is specified, wait until something arrives from that
-     process.  The return value is true iff we read some input from
+     process.  The return value is true if we read some input from
      that process.
 
    If JUST_WAIT_PROC is non-nil, handle only output from WAIT_PROC
      (suspending output from other processes).  A negative value
      means don't run any timers either.
 
-   If WAIT_PROC is specified, then the function returns true iff we
+   If WAIT_PROC is specified, then the function returns true if we
      received input from that process before the timeout elapsed.
-   Otherwise, return true iff we received input from any process.  */
+   Otherwise, return true if we received input from any process.  */
 
 int
 wait_reading_process_output (time_limit, microsecs, read_kbd, do_display,
@@ -7356,7 +7356,7 @@ Lisp_Object QCtype;
    do_display != 0 means redisplay should be done to show subprocess
    output that arrives.
 
-   Return true iff we received input from any process.  */
+   Return true if we received input from any process.  */
 
 int
 wait_reading_process_output (time_limit, microsecs, read_kbd, do_display,
diff --git a/src/process.h b/src/process.h
index 79875564766..eaed95fe4b7 100644
--- a/src/process.h
+++ b/src/process.h
@@ -138,7 +138,7 @@ extern Lisp_Object chan_process[];
 /* Alist of elements (NAME . PROCESS).  */
 extern Lisp_Object Vprocess_alist;
 
-/* True iff we are about to fork off a synchronous process or if we
+/* True if we are about to fork off a synchronous process or if we
    are waiting for it.  */
 extern int synch_process_alive;
 
diff --git a/src/regex.c b/src/regex.c
index 64bfef15c4e..66b84c9dfc2 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -2048,7 +2048,7 @@ re_wctype (str)
   else return 0;
 }
 
-/* True iff CH is in the char class CC.  */
+/* True if CH is in the char class CC.  */
 boolean
 re_iswctype (ch, cc)
      int ch;
diff --git a/src/search.c b/src/search.c
index 4ae3a68b304..d91110f4b0e 100644
--- a/src/search.c
+++ b/src/search.c
@@ -1662,7 +1662,7 @@ simple_search (n, pat, len, len_byte, trt, pos, pos_byte, lim, lim_byte)
    have nontrivial translation are the same aside from the last byte.
    This makes it possible to translate just the last byte of a
    character, and do so after just a simple test of the context.
-   CHARSET_BASE is nonzero iff there is such a non-ASCII character.
+   CHARSET_BASE is nonzero if there is such a non-ASCII character.
 
    If that criterion is not satisfied, do not call this function.  */
 
diff --git a/src/systime.h b/src/systime.h
index 85c2799f083..8b1b7f56ad6 100644
--- a/src/systime.h
+++ b/src/systime.h
@@ -67,7 +67,7 @@ extern time_t timezone;
    EMACS_SECS (TIME) is an rvalue for the seconds component of TIME.
    EMACS_SET_SECS (TIME, SECONDS) sets that to SECONDS.
 
-   EMACS_HAS_USECS is defined iff EMACS_TIME has a usecs component.
+   EMACS_HAS_USECS is defined if EMACS_TIME has a usecs component.
    EMACS_USECS (TIME) is an rvalue for the microseconds component of TIME.
         This returns zero if EMACS_TIME doesn't have a microseconds component.
    EMACS_SET_USECS (TIME, MICROSECONDS) sets that to MICROSECONDS.
@@ -83,7 +83,7 @@ extern time_t timezone;
 
    EMACS_SUB_TIME (DEST, SRC1, SRC2) subtracts SRC2 from SRC1 and
         stores the result in DEST.  SRC should not be negative.
-   EMACS_TIME_NEG_P (TIME) is true iff TIME is negative.
+   EMACS_TIME_NEG_P (TIME) is true if TIME is negative.
 
 */
 
diff --git a/src/systty.h b/src/systty.h
index 15dd7a4e26c..c89edfc8d93 100644
--- a/src/systty.h
+++ b/src/systty.h
@@ -297,7 +297,7 @@ static struct sensemode {
    written before making the change.
    Return 0 if all went well, and -1 if anything failed.
 
-   EMACS_TTY_TABS_OK (struct emacs_tty *P) is false iff the kernel
+   EMACS_TTY_TABS_OK (struct emacs_tty *P) is false if the kernel
    expands tabs to spaces upon output; in that case, there is no
    advantage to using tabs over spaces.  */
 
diff --git a/src/termhooks.h b/src/termhooks.h
index 889c3ab1ab7..eb074608e19 100644
--- a/src/termhooks.h
+++ b/src/termhooks.h
@@ -201,7 +201,7 @@ extern void (*judge_scroll_bars_hook) P_ ((struct frame *FRAME));
 /* Input queue declarations and hooks.  */
 
 /* Expedient hack: only provide the below definitions to files that
-   are prepared to handle lispy things.  CONSP is defined iff lisp.h
+   are prepared to handle lispy things.  CONSP is defined if lisp.h
    has been included before this file.  */
 #ifdef CONSP
 
diff --git a/src/textprop.c b/src/textprop.c
index 711ee571af6..8ce5656e5a2 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -1633,8 +1633,8 @@ Return t if any property was actually removed, nil otherwise.  */)
      The flag `modified' records if changes have been made.
      When object is a buffer, we must call modify_region before changes are
      made and signal_after_change when we are done.
-     We call modify_region before calling remove_properties iff modified == 0,
-     and we call signal_after_change before returning iff modified != 0. */
+     We call modify_region before calling remove_properties if modified == 0,
+     and we call signal_after_change before returning if modified != 0. */
   for (;;)
     {
       if (i == 0)
diff --git a/src/w32term.c b/src/w32term.c
index 3cf9b839559..6f97426d499 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -4401,7 +4401,7 @@ w32_read_socket (sd, expected, hold_quit)
                   /* Window will be selected only when it is not
                      selected now and last mouse movement event was
                      not in it.  Minibuffer window will be selected
-                     iff it is active.  */
+                     only when it is active.  */
                   if (WINDOWP(window)
                       && !EQ (window, last_window)
                       && !EQ (window, selected_window))
diff --git a/src/w32term.h b/src/w32term.h
index d809992b8ff..b73dcfc9ee2 100644
--- a/src/w32term.h
+++ b/src/w32term.h
@@ -198,7 +198,7 @@ struct w32_display_info
   char *w32_id_name;
 
   /* The number of fonts actually stored in w32_font_table.
-     font_table[n] is used and valid iff 0 <= n < n_fonts. 0 <=
+     font_table[n] is used and valid if 0 <= n < n_fonts. 0 <=
      n_fonts <= font_table_size. and font_table[i].name != 0. */
   int n_fonts;
 
diff --git a/src/window.c b/src/window.c
index f1c3a6e49f2..6fe78166ba1 100644
--- a/src/window.c
+++ b/src/window.c
@@ -557,6 +557,15 @@ use  (let ((edges (window-edges))) (- (nth 2 edges) (nth 0 edges))).  */)
   return make_number (window_box_text_cols (decode_any_window (window)));
 }
 
+DEFUN ("window-full-width-p", Fwindow_full_width_p, Swindow_full_width_p, 0, 1, 0,
+       doc: /* Return t if WINDOW is as wide as its frame.
+WINDOW defaults to the selected window.  */)
+     (window)
+     Lisp_Object window;
+{
+  return WINDOW_FULL_WIDTH_P (decode_any_window (window)) ? Qt : Qnil;
+}
+
 DEFUN ("window-hscroll", Fwindow_hscroll, Swindow_hscroll, 0, 1, 0,
        doc: /* Return the number of columns by which WINDOW is scrolled from left margin.
 WINDOW defaults to the selected window.  */)
@@ -7515,6 +7524,7 @@ The selected frame is the one whose configuration has changed.  */);
   defsubr (&Swindow_buffer);
   defsubr (&Swindow_height);
   defsubr (&Swindow_width);
+  defsubr (&Swindow_full_width_p);
   defsubr (&Swindow_hscroll);
   defsubr (&Sset_window_hscroll);
   defsubr (&Swindow_redisplay_end_trigger);
diff --git a/src/window.h b/src/window.h
index 7fc97448757..ea8965392c4 100644
--- a/src/window.h
+++ b/src/window.h
@@ -777,6 +777,7 @@ extern Lisp_Object window_from_coordinates P_ ((struct frame *, int, int,
 EXFUN (Fwindow_dedicated_p, 1);
 extern int window_height P_ ((Lisp_Object));
 extern int window_width P_ ((Lisp_Object));
+EXFUN (Fwindow_full_width_p, 1);
 extern void set_window_height P_ ((Lisp_Object, int, int));
 extern void set_window_width P_ ((Lisp_Object, int, int));
 extern void change_window_heights P_ ((Lisp_Object, int));
@@ -818,7 +819,7 @@ extern int command_loop_level;
 
 extern int minibuf_level;
 
-/* true iff we should redraw the mode lines on the next redisplay.  */
+/* true if we should redraw the mode lines on the next redisplay.  */
 
 extern int update_mode_lines;
 
diff --git a/src/xterm.c b/src/xterm.c
index 2d9de86a445..a5bb506f035 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -6700,7 +6700,7 @@ handle_one_xevent (dpyinfo, eventp, finish, hold_quit)
 
                 /* Window will be selected only when it is not selected now and
                    last mouse movement event was not in it.  Minibuffer window
-                   will be selected iff it is active.  */
+                   will be selected only when it is active.  */
                 if (WINDOWP (window)
                     && !EQ (window, last_window)
                     && !EQ (window, selected_window))
diff --git a/src/xterm.h b/src/xterm.h
index 65499d45b0f..edb35c199f4 100644
--- a/src/xterm.h
+++ b/src/xterm.h
@@ -253,7 +253,7 @@ struct x_display_info
   char *x_id_name;
 
   /* The number of fonts actually stored in x_font_table.
-     font_table[n] is used and valid iff 0 <= n < n_fonts.  0 <=
+     font_table[n] is used and valid if 0 <= n < n_fonts.  0 <=
      n_fonts <= font_table_size and font_table[i].name != 0.  */
   int n_fonts;