F vs F/A vs A…etc

So who decides how aircraft are actually designated in the US anyway? Sure, there’s the system set down from 1962, which you can read about here: http://www.designation-systems.net

But what makes an aircraft an F, an F/A, or an A?

F/A-22: can drop JDAMs and fire AMRAAMs. F/A
F-14D: can drop LGBs and fire AIM-54s. F.
F-117: can drop PGMs and has no A/A ability whatsoever, F.

If you agree with the F/A-22, then shouldn’t it also be F/A-14D and A-13? A-13 because that’d probably be the next A designator, A-12 was the Flying Dorito.

And what about F/A-15E? Or K/F/A-18E/F? People need to be consistent and stop giving me reasons to start asinine threads like this one 😀