Awfully glad I asked, and thank you all for your helpful answers. What I take from them is that I should continue the process I've undertaken of adding to the profiles of my family that I've made, and work to find more, and more accurate, sources; and if FAG (as a gay man, let me say how wrong that looks, tee hee!) is all I have, to enter it in the date field but note it - in Research Notes, I assume, and something in the reason-for-change field if it's a later change. Still not sure what that would look like, though; something like 'Note: FAG only source for death date'? And again, thank you all!