Hi Rob,
I can't really see much point in continuing this thread - it's now gone way off-topic and your perverse refusal to comprehend simple statements leads me to suspect you of trolling (despite the smiley).
But just in case you're not, I'll yet again try to explain the situation in as simple a way as I can.
My "belief" (as you call it) is that terminus ad quem and terminus a quo (for upper and lower limits, respectively) are standard terminology used by scholars of literature engaged in dating texts and other documents. It may not be the terminology used by archaeologists, but the two disciplines are different despite your failure to see it. Forgive me if I'm not swayed from my "belief" by your assertion (which I'm happy to accept) that the other terminology is used in archaeology. I've read enough academic works concerning themselves with dating texts to be sure of the correct usage.
A photograph is a document of sorts, so I used the term that applies to documents, not pottery shards.
Look at your own example again (it uses my term in the context of dating a manuscript) and ask yourself if a manuscript is a document or not.
Please read closely my original use of the Latin term, and permit me to paraphrase it thus: Can the copyright notice be used as a terminus ad quem for the photograph? Do you really argue that this is incorrect usage because the answer is "no"? If so I'm at a loss to understand you. If I was colourblind and asked "is the ball red?" would my use of the word "red" be wrong if the ball was found to be green?
I hope that's clarified things for you. But if not, please don't expect me to be drawn again. Feeding time is over.
Regards,
Stovepipe