Joined: 30 Nov 2013 Posts: 780 Location: The Universe
Not necessarily. It's possible for an unauthorized program to open a data set without updating the reference date. Notice I said "possible." It's legal, does not require anything underhanded, but it's an Assembler "trick" that is not available to high level languages. I have one program that does it. This program is doing an open for input. I don't know what would happen with an open for output.
If I recall correctly it's documented, but finding it is not so easy. I recall putting out a query in one of these forums and someone told me about the trick maybe 15 years ago.