iRule to log HTTP Request

The problem is that i can't find the correspondance between my Request logging profile template variables ($DATE_NCSA, $HTTP_REQUEST, $VIRTUAL_NAME...) and iRule ones.

what about these?

% clock format [clock seconds] -format {%d/%m/%y:%H:%M:%S %Z}
11/08/14:00:49:41 PDT

HTTP (HTTP::method, HTTP::uri, HTTP::version)

virtual name