En passant — a lesser known chess move
en.wikipedia.org
en.wikipedia.org
EDIT: I see now the title has been changed to "En passant — a lesser known chess move". I replied when the title said it was an "Unfairly unknown" move
I am not a professional chess player by any means but have played against a lot of people over the years and never seen this move and that is what I wanted to convey with my title.