No names should be trademarks,
No names should be obviously based on popular game/movie/book characters,
No names should be offensive, insultive, or contain slurs or deliberately mis-spelled alternatives to these,
Names should be proper roleplay names- not objects or words that create a sentence, amusing or otherwise.
So, examples of bad names:
Addidas, Tesco, Legolas, Sonic TheHedgehog, Iama God, Ping Pong, Psycho Idiot, etc.