jenkinsci/perforce-plugin — pull request #46 by jkapica (2014-04-03 15:32:41+00:00)
Title: p4.prog reporting feature

This patch provides capability to report custom p4 program name to the Perforce server.

p4.prog is an arbitrary string which identifies the application establishing connection to p4 server. It can be later traced in server logs as well as with p4 monitor. It is very useful if you have several automated systems connecting to p4 server, and you want to be able to easily trace and account them.

Javadoc is pretty scanty about the parameter, below link to python docs:
http://www.perforce.com/perforce/doc.current/manuals/p4script/03_python.html#1120041