Personally I thought the rule had been scrapped at the start of this season, but it looks like I was wrong. Therefor I would like to remind you all that I will keep a look out for those who break it.
The rule which I'm talking about is about leaving the lobby before the end of the race after you retired. You're not allowed to do it, as it appears to have a high risk of causing frame drops or fps issues to other drivers who are still racing and potentially causing incidents because of it.
The league rules state the following:
● 5 penalty points for leaving the session, without a valid reason (currently only applies for PC)