Used in instant messaging to represent 'Of course'

Of Fucking Course.

Many random internet people use it as of course, but the origin of this acronym is Of Fucking Course.

Used in Instant Messaging for Of Course (Of Fucking Course if in all caps)

Original Female Character. Used in fanfiction when an original character is inserted into an already existing set of characters/fandom. Often shunned due to fear of Mary Sues, hence it is given as a warning.

Original Female Character inserted into fanfiction. A female OC.

out of character

an acronym for "opportunity for change." it's a sweet program for teenage fuckups at brookline high school.
lovingly referred to as "the o" and "opportunity for criminals" and "officially fucked children."