i cant figure out what zipping is im trying so hard i cant find anything on it please help i have looked everywhere i can see it in the run categories but i cant find anything other than you need over 250fps

I zip is the trick that uses the zipline to warp to the end of a stage in back to school, or into the cinema in uniform hunt. With a high fps, all you need to do is to jump of the first zipline in one of those stages, and wait a little while then get back on the zipline. It is demonstrated in the ILs for those stages.