Its hard to actually go and say what the terms are.

Can't be complete without peverreenk.

I'd say High Profile: A player who is likely to be targeted by investigations/abilities in the first few rounds due to their name.
For example, Sasaki, Ichigo and ATPG are high profile.

Write-up: A summary posted by the host at the end of a phase that details the events and progresses the game.

Bandwagon: A sometimes non-existant case that suddenly steamrolls in momentum. Can be used in "third on the bandwagon" reasoning. Also see: 'khaan.

Scumtell: Something that points to a player being mafia, due to actions they have performed. Could comprise of words, post length, and attitude amongst other things.

Rules: A number of rules which used to be true, but now is a sidegame for entertainment. See: Rule #1.

Role PM: A private message sent by the host at the start of the game, informing the player of what role he will take in the game.

I'm sure I'll think of others as I come to them.