Couple of ancient 1960s manuals on eBay

Thats a slightly older version. IBM manuals started out with numbers like "ANN-MMM-VV". I think the letter defines the manual type, most of the ones I have are "C" which I think are general user manuals, "Y" is an internals manual, "A" seems to be hardware , "NN" defines the product, so VM are 20, OS/360 are 28, S/360. The next four identify the manual and the last one is the version. Some time after S/360 came out they added an extra letter on the front, so "G" manuals are general distributed, "S" manuals were only available to licensed users and there are more for "Internal Use Only" manuals. So the one on E-Bay was "H20-0205-3" , which is issue "3" of the SSP manual. The one I have is "GH20-0205-4" so its later as its Version 4 and its got the "G" for a general release manual... but I bet you al knew that...