Well AU is alternative universe, meaning that either key parts have been missed out or totally ignored.
OC mean original character.
OOC - out of character, relatively simple. Lime - sexually suggestive situation Lemon - sexual situation WiP - Work in Progress PwP - essentially just a fic involving a sexual situation with no real plot to it. Slash or yaoi - male/male relationships Femmeslash or yuri - female/female relationships Canon - sticks to the original publication, generally regarding relationships.
I hope that helps =].
like AU/OC ... i only know like two of them and there are a lot otherss and i be really confused.
Can you be more specific? Are there any abbreviations in particular...? =]