What constitutes a useless thread?

Many times I have been infracted for posting in a 'useless thread' but what the hell makes it such?

inb4 this is one, no, just no.

a thread with a nonsensical topic, usually. that, or a thread that's more of a statement than an inquiry for opinion, something you can't really contribute anything to.

ok, got it.

Nonsense questions and statements.

Thanks KiT, and thanks for not trolling/fracting me :3

no reason to if you're trying to educate yourself on the rules.