Permanent Bans

Actually I was also curious to know something about bans.
For example, if someone was banned on the forums only, does that mean he can still play in game without using the forums? Or a forum ban includes also a game ban?
I also wanted to know, if a player was banned, possibly permanently, but it has been a long time since the ban was issued - lets say, over a year - is the ban still valid?
After reading the rules, I failed to understand completely how it works. There are statements in the rules which don't make these things 100% clear, to be honest.
Thank you.