Use QuarkXPress Layouts for Revisions

One powerful use of the Layout feature in QuarkXPress is to save previous revisions of a document. For example, when you want to revise a Project that contains just one Layout (as most Projects do), rather than duplicating the entire Project, just duplicate the Layout. That way, the original version of your Layout is kept alongside the new version of your Layout in the same Project file (rather than as a separate document on your hard drive).

To do that choose Layout> Duplicate…