At the moment if I add custom blank keyword to my scenario using -key KEYWORD '', when injected in SIP message (via [KEYWORD]), it is still rendered as '' (similar for double quotes). Command-line construct like -key KEYWORD (no value passed at all) seems to break parameter parsing (juding by error messages that I've seen).

Is there a way to define an empty keyword, such that when injected in a SIP message it is rendered without quotes?