Yes, I understand that but I would ask why you feel that photograph needs an "identifier"? If it's a stock shot it'll presumably have a file name or can be given a catalogue number. If it's a piece of fine art and you feel it absolutely must be identifiable from the title, presumably the most simple descriptive title sufficient to distinguish it from others is sufficient? – e.g. 'Leg, Loudon, 2017'.
Dear Ian,
For the first point, simple memorability: an alphanumeric accession identification means absolutely nothing, whereas a title tells you (or should in my view tell you) something useful about the picture, to help you remember it.
For the second point, we are in fundamental agreement except over one basic consideration: what constitutes "the most simple descriptive title sufficient to distinguish it from others". For me, this IS the title I used. My memory is crowded. "Plaster leg in magazine rack" stimulates a lot more neurons than just "leg"; and I find the date completely irrelevant except for placing a picture by someone else in historical context. I have taken tens of thousands of pictures over the last half century. Many have appeared in books -- others' books as well as my own -- and in magazines, quite apart from on line; and I have had quite a few exhibitions.
Also, I have used many others' pictures in my books and magazine articles. For some years now, I have had a regular weekly column in Amateur Photographer magazine, Final Analysis.
Here is an example. For others, Google "Roger Hicks Final Analysis".
In all this, memorable identifiers are invaluable. I do not propose that my ideas will work for everyone: "one size fits all" is normally a recipe for disaster. But if you are serious about your photography, and reasonably competent, the chances are that sooner or later your pictures will fall into the hands of those who use words to describe them. Indeed if they do not, your pictures are quite likely always to remain little known. It is, therefore, rarely a bad idea to furnish your pictures with a unique, memorable, verbal identifier.
Cheers,
R.