A response designed to point out, on an internet messageboard or similar, that a person (the target of the command) is unfamiliar with certain inside jokes (meme), has not been around very long, or is a generally inept poster who needs to contribute less to the conversation (lurk) until he/she is more informed.
1337n00b: Can someone explain why that guy is in so many photoshops? I mean, sure he looks funny, but...
What a gatekeeping asshole says on a message board such as Reddit to a new user who doesn't understand an inside joke.
User A: <Says inside joke and gets upvoted by other users who got the joke>
User B: What does <inside joke> mean?
User C: Lurk more peasant User A: Fuck you prick
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi