Short for "it did not happen". Used by lazy people in chatrooms and IMs to save on typing. The extremely lazy ones may not capitalize the letters.
A: I am currently making the cookies :3
B: A, pics or IDNH
A: :|
A: you'll see eventually
A: be patient
B: A, pics or IDNH
A: :|
A: you'll see eventually
A: be patient
by lezboyd.i.am January 1, 2013