A person who ALWAYS goes by the rules in ANY situation.
*Last day of school, kids in class with no work to do*
Kid: Excuse me miss, can I listen to my iPod?
Teacher: No! It is against school policy! You can't listen to your iPod during school! You shouldn't even be bring it to school!
Kid: *Turns to friend who's listening to conversation*
Kid: What a stickler.