diff --git a/reference/strings/functions/number-format.xml b/reference/strings/functions/number-format.xml
index 4565e669cd..783c03f58c 100644
--- a/reference/strings/functions/number-format.xml
+++ b/reference/strings/functions/number-format.xml
@@ -85,12 +85,18 @@
        Sets the thousands separator.
       </para>
       <para>
-       Only the first character of <parameter>thousands_sep</parameter>
+       Only the first byte of <parameter>thousands_sep</parameter>
        is used. For example, if you use <literal>&amp;amp;</literal> as
        <parameter>thousands_sep</parameter> on the number
        <literal>1000</literal>, <function>number_format</function> will
        return <literal>1&amp;000</literal>.
       </para>
+      <para>
+       As noted above, this function only takes the first byte for the 
+       separator. This means that multibyte characters will 
+       <emphasis>NOT</emphasis> work, resulting in a broken multibyte 
+       sequence.
+      </para>
      </listitem>
     </varlistentry>
    </variablelist>