In case I decide that I want to prevent the save. The best way, I suppose is to create a .accde version, but this is a stopgap process.
I was hoping that there was an event with a cancel parameter or a macro that is similar to the autoexec.
Since the Navigation Panel and Ribbon are closed programmatically and the F11 key has an AutoKeys macro, there is not much that can be done. It was more of an exercise to detect the keystroke in case it might be useful in another context. Excel has a BeforeSave event. I thought there might be something similar.
You can intercept keystrokes on the active form if you set Form->Property Sheet -> Events -> Key Preview to yes.
You have not explained why intercepting CTL S would be of any interest, and what the point of that intercept would be. "Preventing Save" does not have any obvious benefits.