Sometimes you want to archive the current version of a page, but still want to roll back to an older version.
For example, you have an annual event page. For eight months of the year, it's all about the upcoming event. For the rest of the year, it's just a short description of the event, and a signup form to be notified when the next event is scheduled. When a the next year's event is scheduled, you want to roll back to last year's event details and make changes, but you don't want to destroy the "pending event" content. The solution is to copy the version of the page that contained last year's event details and go from there. Here's how:
Access the Page Versions list by following the steps on Accessing Versions.
Check the version of the page you wish to copy.
Press the Copy Version button (circled plus icon).
The new copy becomes the current (unapproved) version of the page. Close the Versions panel and reload the page see the current version.