diff --git a/reference.html b/reference.html
index e1147d8..f937b43 100644
--- a/reference.html
+++ b/reference.html
@@ -248,7 +248,7 @@ can be literals (unquoted strings), strings, or numbers
   <dt>INT( <var>aexpr</var> )<dd>Integer part of number
   <dt>LOG( <var>aexpr</var> )<dd>Natural log of number
   <dt>RND( <var>aexpr</var> )<dd>Pseudo-random number generator (0 repeats last, negative reseeds)
-  <dt>SGN( <var>aexpr</var> )<dd>Sign of number (-1,0,1)
+  <dt>SGN( <var>aexpr</var> )<dd>Sign of number (-1, 0, 1)
   <dt>SIN( <var>aexpr</var> )<dd>Sine of number
   <dt>SQR( <var>aexpr</var> )<dd>Square root of number
   <dt>TAN( <var>aexpr</var> )<dd>Tangent of number