diff --git a/src/hb-font.cc b/src/hb-font.cc
index 6919089d3..93510a1fd 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -2288,6 +2288,7 @@ hb_font_set_funcs_data (hb_font_t         *font,
  * as well has draw / paint API output values.
  *
  * Fonts default to a scale equal to the UPEM value of their face.
+ * A font with this setting is sometimes called an "unscaled" font.
  *
  * Since: 0.9.2
  **/