Mika, Do you actually mean that the user part of the URI needs to be duplicated into the display name? Something like the following? subst('/^To:(.*)sip:([^@]*)@([^;]*)(.*)$/To:\1"\2"<sip:\2@\3>\4/ig') Or that the To: display name needs to be rewritten based on content pre-stored in a database (for example because the users have to pre-register via a web GUI)? In that case you could combine a line like avp_db_load( "$to/username", "$avp(label)" ) with a subst (for example replacing the first \2 in the example above with $avp(label), I guess). Finally, if the username/display-name pairs aren't pre-registered, you could store them in the AVP database (using the username or username+domain as a key) at the time the user registers/subscribes, and then retrieve them when processing NOTIFYs (using the avp_db_load() + subst() combination). HTH, S. PS: I haven't tested any of this, although I do use a subst() on To: similar to the one I showed. -- http://carrierclass.net/ http://www.linkedin.com/in/stephalnet