I'm trying to figure out the structure better of a Arch Linux package repository mirror. There's several folders which are pretty easy to understand, such as community, core, extra, multilib, iso, kde-unstable, gnome-unstable, etc.
But there are some others also that are slightly more confusing, such as pool, project, etc.
For example, this is the structure of the mirror http://mirror.gnomus.de/
../ community/ community-staging/ community-testing/ core/ extra/ gnome-unstable/ iso/ kde-unstable/ multilib/ multilib-staging/ multilib-testing/ pool/ project/ staging/ testing/ lastsync lastupdate
Is there a linux mirror tradition I'm missing here, or is this structure unique to Arch? Also, what do the less obvious folders mean? From what I can gather, it seems as though the pool folder contains all of the packages, while the rest categorize them, but I'm not sure if this is right.