Agnosticism is the belife that nothing is known or can be known about non-material phenomena.
Some agnostics believe that the truth about supernatural forces or beings can be known, but we just haven't discovered the answers yet.
Well, I'm just a plan old unmodified agnostic.
There are also people who call themselves vegans, but believe it's fine to exploit animals. People are always fashioning sloppy versions of a system of ideas or ideals and trying to play it off as the real thing.
@Sknydpr, theism is the "belief in the existence of a god or gods." It doesn't mean religion. It just happens that people who believe in a god or gods tend to be religious, but the doesn't mean all religions are theist. Just like all women are humans doesn't mean all humans are women.