Minor documentation improvement.
diff --git a/include/freetype/freetype.h b/include/freetype/freetype.h
index 80a3b63..3780a28 100644
--- a/include/freetype/freetype.h
+++ b/include/freetype/freetype.h
@@ -258,6 +258,7 @@ FT_BEGIN_HEADER
/* x_ppem :: The horizontal ppem value (in 26.6 fractional format). */
/* */
/* y_ppem :: The vertical ppem value (in 26.6 fractional format). */
+ /* Usually, this is the `nominal' pixel height of the font. */
/* */
/* <Note> */
/* The values in this structure are taken from the bitmap font. If */