I do know what "source control" is but even when I wasn't working for myself, my boss made me still add this stuff, despite knowing at the end, upon saving, it would ask what changes were made.

We used something called "Source Safe" from Microsoft.

As for what's in the Notes and deleting it upon live production... that is the old stuff... in case the new stuff stopped working for whatever reason.

I guess we all have our own methods of doing things. Fortunately, I've not had major issues, though everything is backed up to it a server upon my completion of work for the day.