diff --git a/doc/modsecurity2-apache-reference.xml b/doc/modsecurity2-apache-reference.xml
index 02b51d94..4196c7af 100644
--- a/doc/modsecurity2-apache-reference.xml
+++ b/doc/modsecurity2-apache-reference.xml
@@ -3035,8 +3035,10 @@ SecRule <emphasis role="bold">XML:/xq:employees/employee/name/text()</emphasis>
 
       <para>In addition to decoding %xx like <literal
       moreinfo="none">urlDecode, urlDecodeUni also </literal>decodes<literal
-      moreinfo="none"> <literal>%uXXXX</literal> </literal>encoding (only the
-      lower byte will be used, the higher byte will be discarded).</para>
+      moreinfo="none"> <literal>%uXXXX</literal> </literal>encoding. If the
+      code is in the range of FF01-FF5E (the full width ASCII codes), then the
+      higher byte is used to detect and adjust the lower byte. Otherwise, only
+      the lower byte will be used and the higher byte zeroed.</para>
     </section>
 
     <section>
@@ -4495,4 +4497,4 @@ SecRule XML "<emphasis role="bold">@validateSchema /path/to/apache2/conf/xml.xsd
       </itemizedlist>
     </section>
   </section>
-</article>
+</article>
\ No newline at end of file