Originally posted by Ajuin
castling is worth 117 ELO points
Simply knowing what en passant is without starting a help forum "Game error!" thread during a game in progress is worth another 58 ELO points all by itself. But, unfortunately, you have to prove that you specifically didn't
not know what en passant was during a game when it was in progress.
Send feedback (link at the bottom of this page) to get a copy of the form you need submit. I think they've begun requiring proper notarization, but it only takes a month or so and it's worth the points.