Definitions for "Out Of Character"
a character from a fic's original continuity who is written with significant differences than their normal portrayal.
To cease your first person interpretation, usually long enough to answer a question posed by a visitor, such as a request for membership information. Removing the hat is the usual indicator that a reenactor is no longer in character.
LARP term Acting as yourself (as opposed to pretending to be your Character). Something that does not exsist in the game but does exsist in the real world (While playing a wizard in a Fantasy LARP game you might have car keys in your pocket but in the game they would not exsist and everyone would pretend they were not there).
This means that the characers' personalities have been changed from those developed in canon. Sometimes, this is done intentionally for humorous or crossover purposes. Other times, it happens unintentionally due to a ficcer's poor writing skills.