Documentation: Var, question, request for update

http://errorprone.info/bugpattern/Var I like this idea, and we are moving to add errorprone soon. The docs are unclear, does this just effect local vars? what about method and constructor arguments? fields? requesting that this documentation be updated to clarify what exactly it's supposed to affect.

If it doesn't affect method/constructor args, can we add that? or another option or does. We've recently revisited our style guide, and decided that final in those cases is optional, but that they should be effectively final. So it would be nice to enforce with error prone if you can't already.