Shorted version of the phrase "In on page 1". It is used on internet forums as a form of gamesmanship to signify that a poster managed to post on the first page of a rapidly expanding thread expected to reach multiple pages.
OP: Look everyone! The forum admin got arrested with a hooker and I have pictures!
2nd Poster: No way!
3rd Poster: IOP1
4th Poster: I heard the hooker was a tranny!
2nd Poster: No way!
3rd Poster: IOP1
4th Poster: I heard the hooker was a tranny!
by millercommamatt May 25, 2011