What the hell is "levelling" ?!?!?!?!!?!?!?
Saying something that you know is wrong/stupid and when someone responds pointing out your mistake, you have levelled them as they should have known that you knew that the statement was wrong/stupid. However, the respondent may be re-levelling i.e. they knew that you were leveling and you should know that they knew that you knew the original statement was wrong or stupid.
It is derived from "Theory of Poker" by D Sklansky, who talked about multilevel thinking in a poker hand and like much of his work has been refined and modified by 2+2 forum members, allowing them to say virtually anything no matter how stupid and if called to task, claim they were levelling, usually with a unintelligble response involving a double negative and a checkbox to avoid being relevelled.