minor doc improvement
diff --git a/include/freetype/freetype.h b/include/freetype/freetype.h
index 8f5755d..0331240 100644
--- a/include/freetype/freetype.h
+++ b/include/freetype/freetype.h
@@ -913,7 +913,8 @@ FT_BEGIN_HEADER
FT_Generic generic;
- /*# the following are only relevant to scalable outlines */
+ /*# the following are only relevant to scalable outlines; */
+ /*# cf. `FT_Bitmap_Size' for bitmap fonts */
FT_BBox bbox;
FT_UShort units_per_EM;