Taken from the thread mentioned above:
"Every member has a title. Which title they have varies on things like post count, user group etc.
Post Count Titles
Smash n00b ~ 0-24 posts
Smash Child ~ 25-99 posts
Smash Journeyman ~ 100-499 posts
Smash Apprentice ~ 500-999 posts
Smash Lord ~ 1,000-2,499 posts
Smash Master ~ 2,500 or more posts
User Group Titles
Smash Awesome ~ Member of the Back Room
Smash Elitist ~ Respected Smasher/tournament holder who heavily influences the Smash Community
Smash Debater ~ Has posting rights in the Debate Hall
Smash Director ~ Conducts Smash Bros. Tournaments
Temporary Debater ~ Can participate in Debate With Your Power
(apply here for any of the above groups)
Contest Champion Title
Smash Writer ~ Placed well in a Write With Your Power contest.
Staff Titles
Moderator ~ Organizes specific room(s)
Super Moderator ~ Has the power to manage and clean up all rooms
Administrator ~ Head honcho of Poké World Forums
Hiemie ~ Pool Room/BRoom Moderator
Other
Banned (6 Points) ~ Has repeatedly broken the rules
Just about every other title ~ Is custom"
And you don't become a moderator, they ask you to become one if one is needed.