smsops: short reference section about variables

src/modules/smsops/doc/smsops_admin.xml

@@ -95,5 +95,19 @@ smsdump();
 		</section>
 	</section><!-- end of functions -->
 
+	<section>
+	<title>Variables</title>
+	<para>Several variables are exported by the module to access the
+	attributes of the SMS.</para>
+	<itemizedlist>
+	<listitem>
+		<para><emphasis>$smsack</emphasis></para>
+		<para><emphasis>$smsbody</emphasis></para>
+		<para><emphasis>$rpdata(key)</emphasis></para>
+		<para><emphasis>$tpdu(key)</emphasis></para>
+	</listitem>
+	</itemizedlist>
+	</section>
+
 </chapter>