[Kamailio-Users] append_rpid_hf add privacy?

Dear friends, I'm trying to give to a user the option to have privacy in a call. I'm trying to do that by adding an extra header with: append_rpid_hf("sip", ";party=calling;id-type=subscriber;privacy=off;screen=no"); I'm using this header in the begining of the kamailio.cfg if(($rU=="99999") || ($rU=="77777")) { append_rpid_hf("sip", "$ru;party=calling;id-type=subscriber;privacy=off;screen=no"); xlog("alx ------- We have rU match --------"); } When I see the sip messages I don't see this extra header added into it. Does anyone had experience in this ? Thank you Alex