Low-Level Font documentation fix

* doc/lispref/display.texi (Low-Level Font): Mention what the data
types the font attributes are (bug#14634).

1 files changed, 4 insertions, 1 deletions

diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index 23758f6be96..492104ddf07 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -3660,7 +3660,10 @@ The font name (a string), in either XLFD, Fontconfig, or GTK+ format.
 @itemx :slant
 @itemx :width
 These have the same meanings as the face attributes of the same name.
-@xref{Face Attributes}.
+@xref{Face Attributes}.  @code{:family} and @code{:foundry} are
+strings, while the other three are symbols.  As example values,
+@code{:slant} may be @code{italic}, @code{:weight} may be @code{bold}
+and @code{:width} may be @code{normal}.
 
 @item :size
 The font size---either a non-negative integer that specifies the pixel