A metaphorical list in which people who are in ill favor with a given individual are placed.

(n) a list of entities exhibiting general disfavorability, particularly as a result of transgression. Presumably these entities will not receive the normal benefits enjoyed by those not on the list.
(v) the act of placing someone on said list.

A shit list is a mental list of things or poeple that have annoyed you recently. usually completed in a mental top 10 of annoyances for the most recent times and used as a public display of annoyance without offending people directly.

The list of banned, blacklisted.

If you don't like a person they are in your shit list AKA Hit List

Something you get put on if you've managed to offend, hurt, humiliate, contradict, disagree, bad mouth, lie, or cheat someone.

Usually happens at work sometimes at home , upon doing something wrong or just straight up not doing it at all.