This seems to be what I need, but I can not define a separator when it is a whitespace. https://www.opensips.org/Documentation/Script-Tran-2-4#toc6 I tried: $avp(clid){s.substr,1, } $avp(clid){s.substr,1,\ } $avp(clid){s.substr,1,\\ } ----------------------------------------------- BR, Alexey http://alexeyka.zantsev.com/