Looking at the file, I'd say you have something stuck.
First of all, these kind of problems can drive you buggy. When I get these, i now submit it immediately to customer service to get it fixed or explained. It saves a lot of frustration, ...and time.
I did find a Datum Target that is "suppressed" or "incomplete". You will only see it when you show datum axis annotations in a drawing... don't ask how I found it, but its there. it may be assigned "A" but there is no way to know.
And then the 2 points have GD&T tolerance control features tied to them and they too are "incomplete" in the fact that I can't seem to find a way to see or show them.
Alas, even with all these features deleted and saved under a new name, the problem still exists. Certainly not the first time I've seen Ghosts.
This was tested in Creo 2.0. I found nothing in parameters, relations, or search to suggest anything was coded with a property name of A.