Should a copy of T0016 be in our environment data library instead of JDFOBJ?

I was working with using the F0016 and the supporting files to save user notes for a custom process and found code (X0016) that referenced T0016. It indicates that it gets the highest Serial Number and saves it in T0016 during the text entry. Then the X0016 is called to remove the record for the Job (Parm = *END). So first I would expect the T0016 to be empty, ours is not. And second I can only find a single copy of the file in JDFOBJ. So I was wondering if that would cause problems if I am running at