Bumping a post isn't against the rules but necroposting is. As a rule of thumb if there has not been a post in a thread for over a year the conversation is no longer relevant. You are allowed to post in old threads and revive them but it needs to be done by adding something new to the conversation.
Simply posting "Bump" does nothing but clutter the forums with conversations that ended years ago. Most of the people in the threads are not even active anymore. If you do wish to revisit an old topic I would generally advise creating a new thread. Feel free to reference the old one with links, etc. but on topic discussions should be relevant to the people that are still active.
Comments on Profile Post by aseryen