Mark a version

The scene saves itself continuously. Marking a version is about naming a moment — "Front truss rigged and patched" — so you can find it again. Ctrl+S opens this dialog. Write the message so it reads as a label, because that is all you will have to go on.

The History dialog (clock icon, top right) lists what you marked, plus the autosave safety points in between — at most one every five minutes:

Restoring records what it replaced first, so it is never the end of the road — but it does clear undo.