How to assign an iRule to a profile?

The default behavior of the X-Forwarded-For header in the HTTP profile (at least in our version) includes the IP address of any server in the chain before it hits the web server. There are other discussions in the forum about this. Using an iRule, we limit the IP address in the X-Forwarded-For header to be just the IP address of the client making the request. It is possible that they have since provided an option in the profile to do this since I recall seeing some discussion about it.

Sorry I interchanged pool and virtual server. Right now we have this X-Forwarded-For iRule assigned to all external facing virtual servers. Since it is used everywhere, it would be nice if it could be assigned to our base HTTP profile. That said, I could see it being difficult to then order iRules among the total collection consisting of base HTTP Profile, child HTTP profiles, and those assigned to a virtual server. It's just that it's a bunch of work to assign a new iRule to all existing virtual servers.