Why use position rather then pid?

[pkulak]

I trying to do some modifiactions and I'm having trouble figuring out how this works, let alone why. For example, when clicking on a link within the "random" category, displayimage.php get's the album, "random" and the position. How could it possibly know the ordering of a random album? Where is it being stored, and why go through all that trouble?

Okay, nevermind. When pos < 0 it's the pid. Looks like I can't delete a thread, so my stupidity shall stay for all to see!