This one pairs with the change order and imported bubble work. Say you roll a job from Rev B to Rev C. The Rev B drawing on the job is now out of spec and has to go, but you couldn't delete it because it had annotations and bubbles attached to it.
There's now a Revision button on the attachment menu. Upload the replacement PDF and Fulcrum copies the annotations across to the new drawing — along with operator responses and in-process tracking — retires the old drawing, and makes the new one primary. It's available on jobs and on items.