Saving Files

Every time I make a change on a return I save it. So let's say I prepared a return on 4/5. I save the file when I  leave the return. Then, on 4/10, I update the return. I save it. In my TurboTax folder, should the 4/5 return be replaced by the 4/10 version, or should it leave me with both?

Also, this may be meaningless, but on one version, the file that is saved has a curvy hyphen before the file name.. So if I've save 4/5 and 4/10, the hyphen will precede one of those returns - sometimes the earlier one and sometimes the later one.

Note that I also save a PDF of the return.

My intention is to delete the earlier file which has been superseded. But before I delete a file, I was wondering if the hyphen means anything.

I'm also curious if you save the "key calculation" worksheets in the PDF - many of which are quite meaningless. Or do you only check "official government forms"?

Thanks.