Minor comment improvement.
diff --git a/include/freetype/ftsystem.h b/include/freetype/ftsystem.h
index 564b4ea..0b415b6 100644
--- a/include/freetype/ftsystem.h
+++ b/include/freetype/ftsystem.h
@@ -320,7 +320,8 @@ FT_BEGIN_HEADER
*
* cursor ::
* This field is set and used internally by FreeType when parsing
- * frames.
+ * frames. In particular, the `FT_GET_XXX' macros use this instead
+ * of the `pos' field.
*
* limit ::
* This field is set and used internally by FreeType when parsing