Wording improvement.

doc/src/sgml/func.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.226 2004/12/02 17:14:54 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.227 2004/12/02 17:39:54 momjian Exp $
 PostgreSQL documentation
 -->
 
@@ -1075,7 +1075,7 @@ PostgreSQL documentation
        <entry><type>text</type></entry>
        <entry>
         Remove the longest string consisting only of characters
-        in <parameter>characters</parameter> (or spaces if not supplied)
+        in <parameter>characters</parameter> (a space by default)
         from the start and end of <parameter>string</parameter>.
        </entry>
        <entry><literal>btrim('xyxtrimyyx', 'xy')</literal></entry>