What is a necropost

somebody please help I don’t know what a necropost is

Posting on a thread that hasn't been posted on in a while.
For example, if it hasn't been posted on in months, you probably shouldn't post unless it's actually relevant to the discussion.

Or even if it is relevant to the discussion

oh oops I might a done that like once sorry

It’s fine if you didn’t know and some people even allow it on their posts. (Eg, @Palladium_standard, me, @Xanderjedi11.) just don’t repeatedly do it or you might get silenced like @EvilandHomophobicKnight.