Sometimes people speaking about Q3 use the words "cess" and "cessrail". Can someone explain me what those words exactly mean?

Here is an example from Q3 FAQ.

quake.ingame.de/forum/threads/253069-Q3-F-A-Q-amp-Tutorials

"all team should cess primary"

Another example from arQon.

www.esreality.com/?a=post&id=293138

"In the particular case of cessrail, it's a combo rather than a single weapon"