At present, there are default titles given to forum members.
These are Junior member, Member & Senior member. The title depends on the member's overall post tally.

We are considering bringing in a multiple title system. But we need suggestions on what titles to give to members. Does anybody have suggestions? Preferably list your suggestions in order of hierarchy.

But yes, you can also set user a defined title. But the default ones need to be more interesting than what they are at present. Perhaps follow a theme such as fantasy or p2p sharing, etc.