The doctrine of trying to avoid being in the public part of a restroom at the same time as a co-worker emerging from a stall after taking a shit, thereby preserving the anonymity of the person you heard violently exploding in the stall next to you.
Typically working in first-in/first-out order, if you go the bathroom and notice that someone is already using a stall (as if anyone wouldn't notice that earthquake fart), you should politely wait in your stall until that person has exited the restroom before you exit your stall. This order can sometimes be disturbed by speed-shitters and reading-a-freaking-novel shitters. If you're just taking a leak, you do not have to wait.
MAIL GUY: I was dropping trou this morning when I heard someone detonate some serious explosive diarrhea in the stall next to me. I waited for him to wash his hands and leave so that he could have his shitter anonymity.
COPY GUY: I bet it was Ray--that guy eats so much crap he's destined for the brown deluge.
MAIL GUY: Thanks to my good pooping manners, we will never know, and he can keep his dignity.