after reading off of lauren's bingo card and retromarking his own, mike and lauren were both ineligibalized for the remainder of the game
reading off someone else's bingo card to verify whether previous squares have already been provided and then marking your card accordingly
"after reading off of lauren's bingo card and retromarking his own, mike and lauren were both ineligibalized for the remainder of the game" What is the definition of "retromarking"?