I acquired an odd card last year and decided to do a write-up about it. I posted in under the 'Fleer' tab and labeled it 'Frank Mustin'
Four cut corners, white mark created by an eraser? and handwriting on it. Frank Mustin was the head of Fleer in 1989 and this card came from his estate following his death in 2018. Could this help explain the mysterious Whiteout variation?