Luke, looking at your JPG reminds me of something... not quite on-topic but meant to be helpful, nonetheless.
Remember, A.F.F. is "above finished floor". To use the value in your graphic as an example: an elevation is
either given as 151'-3 1/16" (where 100'-0" is at finished floor, for example), or as 51'-3 1/16" A.F.F.
151'-3 1/16" A.F.F. would indicate one hundred fifty one-plus feet above the finished floor (presumably incorrectly).
It's just one of those things that I occasionally see done incorrectly... not that YOU would [have], necessarily.
(And for all I know, you're working with skyscrapers... and your project is a reeeeeeeally tall building!)