2018-04-23 05:05 PM
There are 9 references to AFIO in RM0316 rev.8 and a whole dozen of them in RM0351rev.6. It's easy to find them by textual search.
AFAIK, AFIO is present only in 'F1, so this is a copy/paste relict.
I haven't checked other RMs (except RM0090 in which the respective mentions are correctly changed to reference GPIO), but I believe this is widespread.
JW