Cache Control with forms

Hi everyone! I have the following problem: I don't want any of my site's pages to be saved on any browser's cache. Yet, I want all HTML forms to keep their data when the user changes to another page without submiting and then comes back using the back button. I have seen changing the session.cache_limiter configuration option to 'private' instead of 'nocache' works to make all forms keep their data, but then all pages are diplayed from the browser's cache even after refreshing several times!. I want a point in between, but I don't know how to get there. By the way, do you know what do the values that session.cache_limiter can take mean? (nocache, private and public) Thanks a lot you are all very kind. Cheers, Diego.