*/*: s/backwards compatibility/backward compatibility/.

23 files changed, 112 insertions, 108 deletions

diff --git a/ChangeLog b/ChangeLog
index d04d57684..1dcd7f962 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2017-05-03  Werner Lemberg  <wl@gnu.org>
+
+	*/*: s/backwards compatibility/backward compatibility/.
+
 2017-05-03  Sascha Brawer  <sascha@google.com>
 	    Werner Lemberg  <wl@gnu.org
 
@@ -127,7 +131,7 @@
 
 	* include/freetype/freetype.h (FT_Render_Mode): Fix order.
 
-	This retains backwards compatibility.
+	This retains backward compatibility.
 
 	Noted by Alexei.
 
@@ -162,7 +166,7 @@
 	horizontally, only applying vertical scaling and hinting.
 
 	At the same time, the behaviour of the `light' auto-hinter gets
-	restored for backwards compatibility: Both vertical and horizontal
+	restored for backward compatibility: Both vertical and horizontal
 	scaling is again based on rounded metrics values (this was changed
 	in a commit from 2017-03-30 as a side effect).  To be more precise,
 	the behaviour is restored for TrueType fonts only; for other font
diff --git a/ChangeLog.21 b/ChangeLog.21
index c36da8fd4..eff9f799d 100644
--- a/ChangeLog.21
+++ b/ChangeLog.21
@@ -9062,7 +9062,7 @@
 	  FT_Glyph_Name_Requester => FT_Face_GetGlyphNameFunc
 	  FT_Name_Index_Requester => FT_Face_GetGlyphNameIndexFunc
 
-	* src/base/ftapi.c: New file.  It contains backwards compatibility
+	* src/base/ftapi.c: New file.  It contains backward compatibility
 	functions.
 
 	* include/freetype/internal/psaux.h, src/cid/cidload.c,
@@ -9246,7 +9246,7 @@
 	  {
 	  } PS_StructRec, *PS_Struct;
 
-	  typedef PS_StructRec  T1_Struct;  /* backwards-compatibility */
+	  typedef PS_StructRec  T1_Struct;  /* backward compatibility */
 
 	Hence, we increase the coherency of the source code by effectively
 	using the `Rec' prefix for structure types.
diff --git a/ChangeLog.22 b/ChangeLog.22
index 481c25ee3..e3aec745a 100644
--- a/ChangeLog.22
+++ b/ChangeLog.22
@@ -605,7 +605,7 @@
 
 	* docs/release: Minor additions and clarifications.
 
-	* docs/CHANGES: Updated to reflect many fixes for backwards
+	* docs/CHANGES: Updated to reflect many fixes for backward
 	compatibility.  Still incomplete.
 
 2006-02-26  David Turner  <david@freetype.org>
@@ -2787,7 +2787,7 @@
 2005-06-15  Kirill Smelkov  <kirr@mns.spb.ru>
 
 	The next release will be 2.2.0, so don't worry about source code
-	backwards compatibility.
+	backward compatibility.
 
 	* include/freetype/ftimage.h (FT_Outline_MoveToFunc,
 	FT_Outline_LineToFunc, FT_Outline_ConicToFunc,
diff --git a/ChangeLog.24 b/ChangeLog.24
index 577ffeddf..796763cd7 100644
--- a/ChangeLog.24
+++ b/ChangeLog.24
@@ -335,7 +335,7 @@
 
 	* include/freetype/ftmoderr.h: Fix commit from 2013-03-11.
 
-	The previous version was not backwards compatible.  Reported by
+	The previous version was not backward compatible.  Reported by
 	Behdad.
 
 2013-03-14  Werner Lemberg  <wl@gnu.org>
diff --git a/ChangeLog.25 b/ChangeLog.25
index 60de5640f..d7fed710d 100644
--- a/ChangeLog.25
+++ b/ChangeLog.25
@@ -244,7 +244,7 @@
 
 	All public FreeType enumeration and flag values are uppercase...
 
-	* include/tttables.h (FT_Sfnt_Tag): Implement it.  For backwards
+	* include/tttables.h (FT_Sfnt_Tag): Implement it.  For backward
 	compatibility, retain the old values as macros.
 
 	* src/base/ftfstype.c (FT_Get_FSType_Flags), src/sfnt/sfdriver.c
diff --git a/ChangeLog.26 b/ChangeLog.26
index 7c1126ab8..c174b6d4c 100644
--- a/ChangeLog.26
+++ b/ChangeLog.26
@@ -563,26 +563,26 @@
 	* src/truetype/ttinterp.c (SUBPIXEL_HINTING): Replaced by...
 	(NO_SUBPIXEL_HINTING, SUBPIXEL_HINTING_INFINALITY,
 	SUBPIXEL_HINTING_MINIMAL): ...new macros.
-	(Direct_Move, Direct_Move_X, Direct_Move_Y): Handle backwards
+	(Direct_Move, Direct_Move_X, Direct_Move_Y): Handle backward
 	compatibility.
 	Updated.
 	(Ins_RS, Ins_FDEF, Ins_ENDF, Ins_CALL, Ins_LOOPCALL, Ins_MD):
 	Updated.
 	(Ins_INSTCTRL): Handle native ClearType mode flag.
 	Updated.
-	(Ins_FLIPPT, Ins_FLIPRGON, Ins_FLIPRGOFF): Handle backwards
+	(Ins_FLIPPT, Ins_FLIPRGON, Ins_FLIPRGOFF): Handle backward
 	compatibility.
 	(Move_Zp2_Point): Ditto.
 	(Ins_SHP): Updated.
-	(Ins_SHPIX): Handle backwards compatibility.
+	(Ins_SHPIX): Handle backward compatibility.
 	Updated.
 	(Ins_MSIRP, Ins_MDAP, Ins_MIAP, Ins_MDRP, Ins_MIRP): Updated.
 	(Ins_ALIGNRP): Updated.
-	(Ins_IUP, Ins_DELTAP): Handle backwards compatibility.
+	(Ins_IUP, Ins_DELTAP): Handle backward compatibility.
 	Updated.
 	(Ins_GETINFO): Handle v38 flags.
 	Updated.
-	(TT_RunIns): Handle backwards compatibility mode.
+	(TT_RunIns): Handle backward compatibility mode.
 	Updated.
 
 2016-05-17  Nikolaus Waxweiler  <madigens@gmail.com>
@@ -606,16 +606,16 @@
 
 	* src/truetype/ttinterp.h (TT_ExecContextRec): Define new fields
 	`subpixel_hinting_lean', `vertical_lcd_lean',
-	`backwards_compatibility', `iupx_called', iupy_called', and
+	`backward_compatibility', `iupx_called', iupy_called', and
 	`grayscale_cleartype' for new hinting mode.
 
 	* src/truetype/ttdriver.c (tt_property_set): Handle v38 and v40
 	interpreters conditionally.
 
 	* src/truetype/ttgload.c (TT_Hint_Glyph): Save phantom points unless
-	in v38 backwards compatibility mode.
+	in v38 backward compatibility mode.
 	Updated.
-	(compute_glyph_metrics): Add v38 backwards compatibility mode
+	(compute_glyph_metrics): Add v38 backward compatibility mode
 	constraint for adjusting advance widths.
 	Updated.
 	(tt_loader_init): Handle new flags `subpixel_hinting_lean',
@@ -1482,7 +1482,7 @@
 
 	Still handle `__FTERRORS_H__'.
 
-	We need this for backwards compatibility.
+	We need this for backward compatibility.
 
 	Problem reported by John Emmas <johne53@tiscali.co.uk>.
 
@@ -4222,7 +4222,7 @@
 
 	[truetype] Support selector index 3 of the INSTCTRL instruction.
 
-	This flag activates `native ClearType hinting', disabling backwards
+	This flag activates `native ClearType hinting', disabling backward
 	compatibility mode as described in Greg Hitchcocks whitepaper.  In
 	other words, it enables unrestricted functionality of all TrueType
 	instructions in ClearType.
diff --git a/configure b/configure
index e4312f9cb..68dbd9919 100755
--- a/configure
+++ b/configure
@@ -15,7 +15,7 @@
 
 rm -f config.mk builds/unix/unix-def.mk builds/unix/unix-cc.mk
 
-# respect GNUMAKE environment variable for backwards compatibility
+# respect GNUMAKE environment variable for backward compatibility
 if test "x$GNUMAKE" = x; then
   if test "x$MAKE" = x; then
     if test "x`make -v 2>/dev/null | egrep 'GNU|makepp'`" = x; then
diff --git a/docs/CHANGES b/docs/CHANGES
index d96be35fc..4413a3291 100644
--- a/docs/CHANGES
+++ b/docs/CHANGES
@@ -342,7 +342,7 @@ CHANGES BETWEEN 2.6.2 and 2.6.3
       to the user.   The exception to this  is `__FTERRORS_H__', which
       must be  sometimes undefined by  the user to get  FreeType error
       strings:  Both this  form and  the new  `FTERRORS_H_' macro  are
-      accepted for backwards compatibility.
+      accepted for backward compatibility.
 
     - Minor improvements mainly to the Type 1 driver.
 
@@ -583,17 +583,17 @@ CHANGES BETWEEN 2.5.5 and 2.6
       compiler warnings.
 
     - Function `FT_Bitmap_New'  has been renamed  to `FT_Bitmap_Init',
-      since  this name  better reflects  its function.   For backwards
+      since  this name  better reflects  its  function.   For backward
       compatibility, the old function name is still available.
 
     - Function   `FT_Get_X11_Font_Format'   has    been   renamed   to
       `FT_Get_Font_Format',  since  this   name  better  reflects  its
-      function.  For backwards compatibility, the old function name is
+      function.  For backward compatibility,  the old function name is
       still available.
 
       Additionally, the header  file macro for this  function has been
       renamed to  `FT_FONT_FORMATS_H' (the old name  `FT_XFREE86_H' is
-      retained for backwards compatibility).
+      retained for backward compatibility).
 
     - Various improvements to the `ftgrid' demo program.
 
@@ -1027,7 +1027,7 @@ index ebcf189..3f2ce6b 100644
   II. MISCELLANEOUS
 
     - The  (top-level)  `configure'  script   now  respects  the  MAKE
-      environment variable to specify a `make' binary.   For backwards
+      environment variable  to specify a `make' binary.   For backward
       compatibility, GNUMAKE still overrides MAKE, though.
 
     - The `ftview'  and `ftdiff'  demo programs have  been redesigned,
diff --git a/include/freetype/freetype.h b/include/freetype/freetype.h
index c3bc7049f..65f8fce2c 100644
--- a/include/freetype/freetype.h
+++ b/include/freetype/freetype.h
@@ -771,7 +771,7 @@ FT_BEGIN_HEADER
     FT_ENC_TAG( FT_ENCODING_WANSUNG, 'w', 'a', 'n', 's' ),
     FT_ENC_TAG( FT_ENCODING_JOHAB,   'j', 'o', 'h', 'a' ),
 
-    /* for backwards compatibility */
+    /* for backward compatibility */
     FT_ENCODING_GB2312     = FT_ENCODING_PRC,
     FT_ENCODING_MS_SJIS    = FT_ENCODING_SJIS,
     FT_ENCODING_MS_GB2312  = FT_ENCODING_PRC,
@@ -2037,7 +2037,7 @@ FT_BEGIN_HEADER
   /*    `num_params' and `params' is used.  They are ignored otherwise.    */
   /*                                                                       */
   /*    Ideally, both the `pathname' and `params' fields should be tagged  */
-  /*    as `const'; this is missing for API backwards compatibility.  In   */
+  /*    as `const'; this is missing for API backward compatibility.  In    */
   /*    other words, applications should treat them as read-only.          */
   /*                                                                       */
   typedef struct  FT_Open_Args_
diff --git a/include/freetype/fterrors.h b/include/freetype/fterrors.h
index 021989d0d..42769fa7b 100644
--- a/include/freetype/fterrors.h
+++ b/include/freetype/fterrors.h
@@ -106,7 +106,7 @@
   /*                                                                   */
   /*   #undefine __FTERRORS_H__                                        */
   /*                                                                   */
-  /* work for backwards compatibility.                                 */
+  /* work for backward compatibility.                                  */
   /*                                                                   */
 #if !( defined( FTERRORS_H_ ) && defined ( __FTERRORS_H__ ) )
 #define FTERRORS_H_
diff --git a/include/freetype/ftsnames.h b/include/freetype/ftsnames.h
index ff888b705..a31654057 100644
--- a/include/freetype/ftsnames.h
+++ b/include/freetype/ftsnames.h
@@ -243,7 +243,7 @@ FT_BEGIN_HEADER
    * @description:
    *   A tag for @FT_Parameter to make @FT_Open_Face ignore typographic
    *   family names in the `name' table (introduced in OpenType version
-   *   1.4).  Use this for backwards compatibility with legacy systems that
+   *   1.4).  Use this for backward compatibility with legacy systems that
    *   have a four-faces-per-family restriction.
    *
    */
@@ -264,7 +264,7 @@ FT_BEGIN_HEADER
    * @description:
    *   A tag for @FT_Parameter to make @FT_Open_Face ignore typographic
    *   subfamily names in the `name' table (introduced in OpenType version
-   *   1.4).  Use this for backwards compatibility with legacy systems that
+   *   1.4).  Use this for backward compatibility with legacy systems that
    *   have a four-faces-per-family restriction.
    *
    */
diff --git a/include/freetype/ftstroke.h b/include/freetype/ftstroke.h
index 8a868089c..4a20667c5 100644
--- a/include/freetype/ftstroke.h
+++ b/include/freetype/ftstroke.h
@@ -136,7 +136,7 @@ FT_BEGIN_HEADER
    *     FT_STROKER_LINEJOIN_MITER_VARIABLE generates a mitered line
    *     join as used in XPS.  FT_STROKER_LINEJOIN_MITER is an alias
    *     for FT_STROKER_LINEJOIN_MITER_VARIABLE, retained for
-   *     backwards compatibility.
+   *     backward compatibility.
    */
   typedef enum  FT_Stroker_LineJoin_
   {
diff --git a/include/freetype/ftttdrv.h b/include/freetype/ftttdrv.h
index 50e1b246a..26bc5e966 100644
--- a/include/freetype/ftttdrv.h
+++ b/include/freetype/ftttdrv.h
@@ -110,7 +110,7 @@ FT_BEGIN_HEADER
    *   TrueType interpreter fully allows the advance width to be adjusted in
    *   this mode, just the DWrite client will ignore those changes.
    *
-   *   _ClearType_ _Backwards_ _Compatibility_
+   *   _ClearType_ _Backward_ _Compatibility_
    *
    *   This is a set of exceptions made in the TrueType interpreter to
    *   minimize hinting techniques that were problematic with the extra
@@ -118,9 +118,9 @@ FT_BEGIN_HEADER
    *   http://www.beatstamm.com/typography/RTRCh4.htm#Sec1 and
    *   http://www.microsoft.com/typography/cleartype/truetypecleartype.aspx.
    *   This technique is not to be confused with ClearType compatible
-   *   widths.  ClearType backwards compatibility has no direct impact on
+   *   widths.  ClearType backward compatibility has no direct impact on
    *   changing advance widths, but there might be an indirect impact on
-   *   disabling some deltas.  This could be worked around in backwards
+   *   disabling some deltas.  This could be worked around in backward
    *   compatibility mode.
    *
    *   _Native_ _ClearType_ _Mode_
diff --git a/include/freetype/internal/psaux.h b/include/freetype/internal/psaux.h
index 286d6040c..935eb1a9c 100644
--- a/include/freetype/internal/psaux.h
+++ b/include/freetype/internal/psaux.h
@@ -817,7 +817,7 @@ FT_BEGIN_HEADER
 
   } PSAux_ServiceRec, *PSAux_Service;
 
-  /* backwards-compatible type definition */
+  /* backward compatible type definition */
   typedef PSAux_ServiceRec   PSAux_Interface;
 
 
diff --git a/include/freetype/internal/tttypes.h b/include/freetype/internal/tttypes.h
index 9a2f7c806..c0758e25f 100644
--- a/include/freetype/internal/tttypes.h
+++ b/include/freetype/internal/tttypes.h
@@ -1383,7 +1383,7 @@ FT_BEGIN_HEADER
   /*                                                                       */
   /*    sph_compatibility_mode ::                                          */
   /*                            This flag is set if we are in ClearType    */
-  /*                            backwards compatibility mode (used by the  */
+  /*                            backward compatibility mode (used by the   */
   /*                            v38 implementation of the bytecode         */
   /*                            interpreter).                              */
   /*                                                                       */
diff --git a/include/freetype/t1tables.h b/include/freetype/t1tables.h
index 81c903453..3f6b36e10 100644
--- a/include/freetype/t1tables.h
+++ b/include/freetype/t1tables.h
@@ -291,7 +291,7 @@ FT_BEGIN_HEADER
 
   } PS_DesignMapRec, *PS_DesignMap;
 
-  /* backwards-compatible definition */
+  /* backward compatible definition */
   typedef PS_DesignMapRec  T1_DesignMap;
 
 
@@ -326,7 +326,7 @@ FT_BEGIN_HEADER
   } PS_BlendRec, *PS_Blend;
 
 
-  /* backwards-compatible definition */
+  /* backward compatible definition */
   typedef PS_BlendRec  T1_Blend;
 
 
diff --git a/include/freetype/ttnameid.h b/include/freetype/ttnameid.h
index 04be3f77c..494d67718 100644
--- a/include/freetype/ttnameid.h
+++ b/include/freetype/ttnameid.h
@@ -1216,7 +1216,7 @@ FT_BEGIN_HEADER
 
   /* */
 
-  /* for backwards compatibility with older FreeType versions */
+  /* for backward compatibility with older FreeType versions */
 #define TT_UCR_ARABIC_PRESENTATION_A         \
           TT_UCR_ARABIC_PRESENTATION_FORMS_A
 #define TT_UCR_ARABIC_PRESENTATION_B         \
diff --git a/include/freetype/ttunpat.h b/include/freetype/ttunpat.h
index 11f6dedc4..f5e417089 100644
--- a/include/freetype/ttunpat.h
+++ b/include/freetype/ttunpat.h
@@ -3,7 +3,7 @@
 /*  ttunpat.h                                                              */
 /*                                                                         */
 /*    Definitions for the unpatented TrueType hinting system.              */
-/*    Obsolete, retained for backwards compatibility.                      */
+/*    Obsolete, retained for backward compatibility.                       */
 /*                                                                         */
 /*  Copyright 2003-2017 by                                                 */
 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
diff --git a/src/base/ftapi.c b/src/base/ftapi.c
index 1e6c718d9..4262d37e3 100644
--- a/src/base/ftapi.c
+++ b/src/base/ftapi.c
@@ -38,7 +38,7 @@
   /*************************************************************************/
   /*************************************************************************/
 
-  /* backwards compatibility API */
+  /* backward compatibility API */
 
   FT_BASE_DEF( void )
   FT_New_Memory_Stream( FT_Library  library,
diff --git a/src/base/ftpatent.c b/src/base/ftpatent.c
index 0925a6256..9900f99bf 100644
--- a/src/base/ftpatent.c
+++ b/src/base/ftpatent.c
@@ -3,7 +3,7 @@
 /*  ftpatent.c                                                             */
 /*                                                                         */
 /*    FreeType API for checking patented TrueType bytecode instructions    */
-/*    (body).  Obsolete, retained for backwards compatibility.             */
+/*    (body).  Obsolete, retained for backward compatibility.              */
 /*                                                                         */
 /*  Copyright 2007-2017 by                                                 */
 /*  David Turner.                                                          */
diff --git a/src/truetype/ttgload.c b/src/truetype/ttgload.c
index 9c1e109c3..b7a844a6c 100644
--- a/src/truetype/ttgload.c
+++ b/src/truetype/ttgload.c
@@ -163,7 +163,7 @@
       /* This may not be the right place for this, but it works...  */
       /* Note that we have to unconditionally load the tweaks since */
       /* it is possible that glyphs individually switch ClearType's */
-      /* backwards compatibility mode on and off.                   */
+      /* backward compatibility mode on and off.                    */
       sph_set_tweaks( loader, glyph_index );
     }
 #endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
@@ -821,11 +821,11 @@
 #endif
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-    /* Save possibly modified glyph phantom points unless in v40 backwards */
+    /* Save possibly modified glyph phantom points unless in v40 backward  */
     /* compatibility mode, where no movement on the x axis means no reason */
     /* to change bearings or advance widths.                               */
     if ( !( driver->interpreter_version == TT_INTERPRETER_VERSION_40 &&
-            !loader->exec->backwards_compatibility ) )
+            !loader->exec->backward_compatibility ) )
     {
 #endif
       loader->pp1 = zone->cur[zone->n_points - 4];
@@ -2053,18 +2053,18 @@
     glyph->metrics.horiBearingY = bbox.yMax;
     glyph->metrics.horiAdvance  = loader->pp2.x - loader->pp1.x;
 
-    /* Adjust advance width to the value contained in the hdmx table    */
-    /* unless FT_LOAD_COMPUTE_METRICS is set or backwards compatibility */
-    /* mode of the v40 interpreter is active.  See `ttinterp.h' for     */
-    /* details on backwards compatibility mode.                         */
+    /* Adjust advance width to the value contained in the hdmx table   */
+    /* unless FT_LOAD_COMPUTE_METRICS is set or backward compatibility */
+    /* mode of the v40 interpreter is active.  See `ttinterp.h' for    */
+    /* details on backward compatibility mode.                         */
     if (
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-         !( driver->interpreter_version == TT_INTERPRETER_VERSION_40 &&
-            ( loader->exec && loader->exec->backwards_compatibility  ) ) &&
+         !( driver->interpreter_version == TT_INTERPRETER_VERSION_40  &&
+            ( loader->exec && loader->exec->backward_compatibility  ) ) &&
 #endif
-         !face->postscript.isFixedPitch                                  &&
-         IS_HINTED( loader->load_flags )                                 &&
-         !( loader->load_flags & FT_LOAD_COMPUTE_METRICS )               )
+         !face->postscript.isFixedPitch                                 &&
+         IS_HINTED( loader->load_flags )                                &&
+         !( loader->load_flags & FT_LOAD_COMPUTE_METRICS )              )
     {
       FT_Byte*  widthp;
 
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index 0c51f756d..af31408cb 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -1656,7 +1656,7 @@
   /*    zone     :: The affected glyph zone.                               */
   /*                                                                       */
   /* <Note>                                                                */
-  /*    See `ttinterp.h' for details on backwards compatibility mode.      */
+  /*    See `ttinterp.h' for details on backward compatibility mode.       */
   /*    `Touches' the point.                                               */
   /*                                                                       */
   static void
@@ -1684,7 +1684,7 @@
       /* Exception to the post-IUP curfew: Allow the x component of */
       /* diagonal moves, but only post-IUP.  DejaVu tries to adjust */
       /* diagonal stems like on `Z' and `z' post-IUP.               */
-      if ( SUBPIXEL_HINTING_MINIMAL && !exc->backwards_compatibility )
+      if ( SUBPIXEL_HINTING_MINIMAL && !exc->backward_compatibility )
         zone->cur[point].x += FT_MulDiv( distance, v, exc->F_dot_P );
       else
 #endif
@@ -1700,10 +1700,10 @@
     if ( v != 0 )
     {
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-      if ( !( SUBPIXEL_HINTING_MINIMAL     &&
-              exc->backwards_compatibility &&
-              exc->iupx_called             &&
-              exc->iupy_called             ) )
+      if ( !( SUBPIXEL_HINTING_MINIMAL    &&
+              exc->backward_compatibility &&
+              exc->iupx_called            &&
+              exc->iupy_called            ) )
 #endif
         zone->cur[point].y += FT_MulDiv( distance, v, exc->F_dot_P );
 
@@ -1756,7 +1756,7 @@
   /*                                                                       */
   /*   The following versions are used whenever both vectors are both      */
   /*   along one of the coordinate unit vectors, i.e. in 90% of the cases. */
-  /*   See `ttinterp.h' for details on backwards compatibility mode.       */
+  /*   See `ttinterp.h' for details on backward compatibility mode.        */
   /*                                                                       */
   /*************************************************************************/
 
@@ -1774,7 +1774,7 @@
 #endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-    if ( SUBPIXEL_HINTING_MINIMAL && !exc->backwards_compatibility )
+    if ( SUBPIXEL_HINTING_MINIMAL && !exc->backward_compatibility )
       zone->cur[point].x += distance;
     else
 #endif
@@ -1796,7 +1796,7 @@
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
     if ( !( SUBPIXEL_HINTING_MINIMAL             &&
-            exc->backwards_compatibility         &&
+            exc->backward_compatibility          &&
             exc->iupx_called && exc->iupy_called ) )
 #endif
       zone->cur[point].y += distance;
@@ -5126,11 +5126,11 @@
 #endif
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-      /* Native ClearType fonts sign a waiver that turns off all backwards */
+      /* Native ClearType fonts sign a waiver that turns off all backward  */
       /* compatibility hacks and lets them program points to the grid like */
       /* it's 1996.  They might sign a waiver for just one glyph, though.  */
       if ( SUBPIXEL_HINTING_MINIMAL )
-        exc->backwards_compatibility = !FT_BOOL( L == 4 );
+        exc->backward_compatibility = !FT_BOOL( L == 4 );
 #endif
     }
   }
@@ -5218,11 +5218,11 @@
 
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-    /* See `ttinterp.h' for details on backwards compatibility mode. */
-    if ( SUBPIXEL_HINTING_MINIMAL     &&
-         exc->backwards_compatibility &&
-         exc->iupx_called             &&
-         exc->iupy_called             )
+    /* See `ttinterp.h' for details on backward compatibility mode. */
+    if ( SUBPIXEL_HINTING_MINIMAL    &&
+         exc->backward_compatibility &&
+         exc->iupx_called            &&
+         exc->iupy_called            )
       goto Fail;
 #endif
 
@@ -5273,11 +5273,11 @@
 
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-    /* See `ttinterp.h' for details on backwards compatibility mode. */
-    if ( SUBPIXEL_HINTING_MINIMAL     &&
-         exc->backwards_compatibility &&
-         exc->iupx_called             &&
-         exc->iupy_called             )
+    /* See `ttinterp.h' for details on backward compatibility mode. */
+    if ( SUBPIXEL_HINTING_MINIMAL    &&
+         exc->backward_compatibility &&
+         exc->iupx_called            &&
+         exc->iupy_called            )
       return;
 #endif
 
@@ -5311,11 +5311,11 @@
 
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-    /* See `ttinterp.h' for details on backwards compatibility mode. */
-    if ( SUBPIXEL_HINTING_MINIMAL     &&
-         exc->backwards_compatibility &&
-         exc->iupx_called             &&
-         exc->iupy_called             )
+    /* See `ttinterp.h' for details on backward compatibility mode. */
+    if ( SUBPIXEL_HINTING_MINIMAL    &&
+         exc->backward_compatibility &&
+         exc->iupx_called            &&
+         exc->iupy_called            )
       return;
 #endif
 
@@ -5378,7 +5378,7 @@
   }
 
 
-  /* See `ttinterp.h' for details on backwards compatibility mode. */
+  /* See `ttinterp.h' for details on backward compatibility mode. */
   static void
   Move_Zp2_Point( TT_ExecContext  exc,
                   FT_UShort       point,
@@ -5389,8 +5389,8 @@
     if ( exc->GS.freeVector.x != 0 )
     {
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-      if ( !( SUBPIXEL_HINTING_MINIMAL     &&
-              exc->backwards_compatibility ) )
+      if ( !( SUBPIXEL_HINTING_MINIMAL    &&
+              exc->backward_compatibility ) )
 #endif
         exc->zp2.cur[point].x += dx;
 
@@ -5401,10 +5401,10 @@
     if ( exc->GS.freeVector.y != 0 )
     {
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-      if ( !( SUBPIXEL_HINTING_MINIMAL     &&
-              exc->backwards_compatibility &&
-              exc->iupx_called             &&
-              exc->iupy_called             ) )
+      if ( !( SUBPIXEL_HINTING_MINIMAL    &&
+              exc->backward_compatibility &&
+              exc->iupx_called            &&
+              exc->iupy_called            ) )
 #endif
         exc->zp2.cur[point].y += dy;
 
@@ -5701,8 +5701,8 @@
       else
 #endif
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-      if ( SUBPIXEL_HINTING_MINIMAL     &&
-           exc->backwards_compatibility )
+      if ( SUBPIXEL_HINTING_MINIMAL    &&
+           exc->backward_compatibility )
       {
         /* Special case: allow SHPIX to move points in the twilight zone.  */
         /* Otherwise, treat SHPIX the same as DELTAP.  Unbreaks various    */
@@ -6466,7 +6466,7 @@
       R.x = FT_MulDiv( val, dax, discriminant );
       R.y = FT_MulDiv( val, day, discriminant );
 
-      /* XXX: Block in backwards_compatibility and/or post-IUP? */
+      /* XXX: Block in backward_compatibility and/or post-IUP? */
       exc->zp2.cur[point].x = exc->zp1.cur[a0].x + R.x;
       exc->zp2.cur[point].y = exc->zp1.cur[a0].y + R.y;
     }
@@ -6474,7 +6474,7 @@
     {
       /* else, take the middle of the middles of A and B */
 
-      /* XXX: Block in backwards_compatibility and/or post-IUP? */
+      /* XXX: Block in backward_compatibility and/or post-IUP? */
       exc->zp2.cur[point].x = ( exc->zp1.cur[a0].x +
                                 exc->zp1.cur[a1].x +
                                 exc->zp0.cur[b0].x +
@@ -6866,11 +6866,11 @@
 
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-    /* See `ttinterp.h' for details on backwards compatibility mode. */
+    /* See `ttinterp.h' for details on backward compatibility mode.  */
     /* Allow IUP until it has been called on both axes.  Immediately */
     /* return on subsequent ones.                                    */
-    if ( SUBPIXEL_HINTING_MINIMAL     &&
-         exc->backwards_compatibility )
+    if ( SUBPIXEL_HINTING_MINIMAL    &&
+         exc->backward_compatibility )
     {
       if ( exc->iupx_called && exc->iupy_called )
         return;
@@ -7112,10 +7112,10 @@
           {
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-            /* See `ttinterp.h' for details on backwards compatibility */
-            /* mode.                                                   */
-            if ( SUBPIXEL_HINTING_MINIMAL     &&
-                 exc->backwards_compatibility )
+            /* See `ttinterp.h' for details on backward compatibility */
+            /* mode.                                                  */
+            if ( SUBPIXEL_HINTING_MINIMAL    &&
+                 exc->backward_compatibility )
             {
               if ( !( exc->iupx_called && exc->iupy_called )              &&
                    ( ( exc->is_composite && exc->GS.freeVector.y != 0 ) ||
@@ -7259,7 +7259,7 @@
     {
       if ( exc->ignore_x_mode )
       {
-        /* if in ClearType backwards compatibility mode,        */
+        /* if in ClearType backward compatibility mode,         */
         /* we sometimes change the TrueType version dynamically */
         K = exc->rasterizer_version;
         FT_TRACE6(( "Setting rasterizer version %d\n",
@@ -7589,15 +7589,15 @@
 #endif /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY */
 
 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
-    /* Toggle backwards compatibility according to what font says, except  */
+    /* Toggle backward compatibility according to what font says, except   */
     /* when it's a `tricky' font that heavily relies on the interpreter to */
-    /* render glyphs correctly, e.g. DFKai-SB.  Backwards compatibility    */
+    /* render glyphs correctly, e.g. DFKai-SB.  Backward compatibility     */
     /* hacks may break it.                                                 */
     if ( SUBPIXEL_HINTING_MINIMAL          &&
          !FT_IS_TRICKY( &exc->face->root ) )
-      exc->backwards_compatibility = !( exc->GS.instruct_control & 4 );
+      exc->backward_compatibility = !( exc->GS.instruct_control & 4 );
     else
-      exc->backwards_compatibility = FALSE;
+      exc->backward_compatibility = FALSE;
 
     exc->iupx_called = FALSE;
     exc->iupy_called = FALSE;
diff --git a/src/truetype/ttinterp.h b/src/truetype/ttinterp.h
index 6625e16c7..55e472091 100644
--- a/src/truetype/ttinterp.h
+++ b/src/truetype/ttinterp.h
@@ -256,7 +256,7 @@ FT_BEGIN_HEADER
      * Modern TrueType fonts are usually rendered through Microsoft's
      * collection of rendering techniques called ClearType (e.g., subpixel
      * rendering and subpixel hinting).  When ClearType was introduced, most
-     * fonts were not ready.  Microsoft decided to implement a backwards
+     * fonts were not ready.  Microsoft decided to implement a backward
      * compatibility mode that employed several simple to complicated
      * assumptions and tricks that modified the interpretation of the
      * bytecode contained in these fonts to make them look ClearType-y
@@ -316,12 +316,12 @@ FT_BEGIN_HEADER
      * very specific patterns (`superhinting') for pre-ClearType-displays,
      * the worse the results.
      *
-     * Microsoft defines a way to turn off backwards compatibility and
+     * Microsoft defines a way to turn off backward compatibility and
      * interpret instructions as before (called `native ClearType')[2][3].
      * The font designer then regains full control and is responsible for
      * making the font work correctly with ClearType without any
      * hand-holding by the interpreter or rasterizer[4].  The v40
-     * interpreter assumes backwards compatibility by default, which can be
+     * interpreter assumes backward compatibility by default, which can be
      * turned off the same way by executing the following in the control
      * program (cf. `Ins_INSTCTRL').
      *
@@ -331,7 +331,7 @@ FT_BEGIN_HEADER
      * [1] Tricky fonts as FreeType defines them rely on the bytecode
      *     interpreter to display correctly.  Hacks can interfere with them,
      *     so they get treated like native ClearType fonts (v40 with
-     *     backwards compatibility turned off).  Cf. `TT_RunIns'.
+     *     backward compatibility turned off).  Cf. `TT_RunIns'.
      *
      * [2] Proposed by Microsoft's Greg Hitchcock in
      *     https://www.microsoft.com/typography/cleartype/truetypecleartype.aspx
@@ -357,10 +357,10 @@ FT_BEGIN_HEADER
     /* is managed differently.                                            */
     FT_Bool            vertical_lcd_lean;
 
-    /* Default to backwards compatibility mode in v40 interpreter.  If  */
+    /* Default to backward compatibility mode in v40 interpreter.  If   */
     /* this is false, it implies the interpreter is in v35 or in native */
     /* ClearType mode.                                                  */
-    FT_Bool            backwards_compatibility;
+    FT_Bool            backward_compatibility;
 
     /* Useful for detecting and denying post-IUP trickery that is usually */
     /* used to fix pixel patterns (`superhinting').                       */