exam and on Stack Overflow seems to be mostly used to indicate that the OP is either cheating on their exam by asking us to do their work for them or, less nefariously, studying for an exam. Either way, it's a useless meta tag. (it's also occasionally used to indicate the OP is writing an exam system, in which case it's instead just a useless keyword that no one would be searching for.)
review is somewhat related in that it's often combined with exam to indicate that OP is reviewing material before an exam. It's also occasionally used to discuss the review processes at various app stores or elsewhere, although IMO it doesn't add much to the questions (if they're even on-topic for SO, which is arguable.)
Can we burninate both of these?