Umatrix:
I would expect that a spec. or std. call-out, on a drawing, would refer the latest ed. of that spec. or std. as of/at the time that the design and drawing were done. If they meant an earlier spec. or std. they should explicitly call that out. And, of course, they couldn’t be referring to unknown future stds. Your current client or contract could indicate that you should follow the current/latest stds. for the work you are now doing, or for parts which must be replaced, etc. There shouldn’t be much doubt that engineers and drafters are a lazy lot, or they might actually show a spec. or std. number and date on the drawing, to save confusion. Alternatively, they could use my favorite new acronym ‘tsIalarn’ on all the drawings, which stands for ‘the spec. I am looking at right now.’