As far as I know, the requirement of the IOCCC has always just been to submit any obfuscated C program. A submitted program can do something interesting, or something ordinary in an interesting way, but there's no specific constraint on what it does.
You might be confusing the IOCCC with the Underhanded C Contest, in which the goal was to do some particular task, but also subvert it in a non-obvious way: http://www.underhanded-c.org/
You might be confusing the IOCCC with the Underhanded C Contest, in which the goal was to do some particular task, but also subvert it in a non-obvious way: http://www.underhanded-c.org/