diff --git a/doc/manuals/vty/sgsn_vty_reference.xml b/doc/manuals/vty/sgsn_vty_reference.xml
index ed11777..e9cd322 100644
--- a/doc/manuals/vty/sgsn_vty_reference.xml
+++ b/doc/manuals/vty/sgsn_vty_reference.xml
@@ -2232,9 +2232,9 @@
     </command>
     <command id='authentication (optional|required)'>
       <params>
-        <param name='authentication' doc='Whether to enforce MS authentication in GERAN' />
-        <param name='optional' doc='Allow MS to attach via GERAN without authentication' />
-        <param name='required' doc='Always require authentication' />
+        <param name='authentication' doc='Whether to enforce MS authentication in GERAN (only with auth-policy remote)' />
+        <param name='optional' doc='Allow MS to attach via GERAN without authentication (default and only possible value for non-remote auth-policy)' />
+        <param name='required' doc='Always require authentication (only available for auth-policy remote, default with that auth-policy)' />
       </params>
     </command>
     <command id='encryption (GEA0|GEA1|GEA2|GEA3|GEA4)'>