iRule

Hi there. I´m a beginner in F5 Equipment, but now I have a problem with iRules concept, can someone to clarify me if, I´m using iRule instead of Ram Cache, my problem is when one user is reaching a web application, the browser of this user is maintaining all cache instructions performed. We don´t want this, our request is to erase all cache in the browser once all activities were finished. This problem could be because I have iRule applied ??