This question follows up on What is the exact purpose of \ftype@<TYPE>?. The LaTeX kernel source refers to a
BANG float in the
ltoutput.dtx, but there is no explanation for it. Anybody knows what it is?
bang float are floats with an "!" float option. I guess the name came from the same source as the bang in "shebang" and "hash-bang" for "#!". http://en.wikipedia.org/wiki/Shebang_(Unix).
In the 1950's, secretarial dictation and typesetting manuals referred to the mark as "bang," most likely adapted from comic books where the ! appeared in dialogue balloons to represent a gun being fired, although the nickname probably emerged from letterpress printing. This bang usage is behind the titles of the interrobang, an uncommon typographic character, and a shebang line, a feature of unix computer systems.