Document module names.
diff --git a/include/freetype/ftmodapi.h b/include/freetype/ftmodapi.h
index acf1366..4cb089d 100644
--- a/include/freetype/ftmodapi.h
+++ b/include/freetype/ftmodapi.h
@@ -48,6 +48,31 @@ FT_BEGIN_HEADER
/* The definitions below are used to manage modules within FreeType. */
/* Modules can be added, upgraded, and removed at runtime. */
/* */
+ /* Here is a list of module names (the possible values of the */
+ /* `module_name' field in the @FT_Module_Class structure). */
+ /* */
+ /* { */
+ /* autofitter */
+ /* bdf */
+ /* cff */
+ /* gxvalid */
+ /* otvalid */
+ /* pcf */
+ /* pfr */
+ /* psaux */
+ /* pshinter */
+ /* psnames */
+ /* raster1, raster5 */
+ /* sfnt */
+ /* smooth, smooth-lcd, smooth-lcdv */
+ /* truetype */
+ /* type1 */
+ /* type42 */
+ /* t1cid */
+ /* winfonts */
+ /* } */
+ /* */
+ /* */
/*************************************************************************/