acc_radius: added more info about response code for acc_rad_request()

modules/acc_radius/doc/acc_radius_admin.xml

@@ -226,7 +226,10 @@ modparam("acc_radius", "rad_time_mode", 1)
 		Meaning of the parameters is as follows:</para>
 		<itemizedlist>
 		<listitem>
-			<para><emphasis>comment</emphasis> - Comment to be appended.
+			<para><emphasis>comment</emphasis> - Comment to be appended. The
+				first token can be a SIP response code that it is wanted to
+				be interpreted as event type (e.g., using 200 means the
+				transaction is considered successfully responded).
 			</para>
 		</listitem>
 		</itemizedlist>
@@ -239,6 +242,7 @@ modparam("acc_radius", "rad_time_mode", 1)
 ...
 acc_rad_request("Some comment");
 ...
+# write record as when the transaction was responded with a 200 code
 acc_rad_request("200 From Config");
 ...
 </programlisting>