How to identify explicitly saved versions when reverting a document?
You can't.

Keep doing the manual versioning series that you should always have been doing. At each milestone save a new copy with a new file title that describes what it is.

All that's new with a Lion Autosave/Versions app is that you'll have to suffer horrifically each time you do so.


Start with your working document, save it as "MyReport - workingcopy".
When you want to save your manual milestone version, first press CMD-S to "Save a Version" (or you may get a dialogue about reverting to a previous version).
Then select File / Duplicate , which will pop up a second window of your open document (not prompt you to save a copy to disk).
The new window will be titled "MyReport - workingcopy copy". This is very confusingly a tentative filename only that doesn't actually exist as a (user accessible) file on your drive yet.
Now press CMD-S to save that open duplicated document window. This will give you the normal file save dialogue where you can rename it "MyReport - Milestone 1".
Now CLOSE THAT NEW DOCUMENT "MyReport - Milestone 1" and go back to working on the previous document "MyReport - workingcopy" -- leaving your new milestone file safe (for now) in its saved state.


If you've cleverly thought of going to System Preferences / Keyboards to create a CMD-D keyboard shortcut for that Duplicate command, TextEdit at least will completely ignore it. 

The shortcut will not appear in the File menu next to the Duplicate menu item. Pressing it will do nothing.