Fanlore:Featured Article Archives/2017: Week 29
An ! or exclamation mark (sometimes called a "bang") between two words denotes a trait!character relationship between them, especially between a character and a trait of that character. For example, CAPSLOCK!Harry refers to Harry Potter shouting in capslock during much of The Order of the Phoenix, while Femme!Blair would refer to a characterization of Blair behaving in fanfiction in a way some might consider stereotypically effeminate. The idea of Dark!Harry has inspired hundreds of fanfics.
The bang relationship can also be used in the noun!fic form, referring to things like wing!fic, crack!fic, rape!fic and so on. However, in this case, it's usually also acceptable to omit the exclamation mark and make it one word, which does not happen for trait!character expressions.