3.7.
Undo!
Up one level
The undo operation is available for undoing one or several recent changes. To undo, click the undo link to the right of your name at the top of the edit area:

After clicking undo, you will see a list of recent changes to the web site, in the order of most recent on top of the list. Click to check the actions you would like to undo, and then click the undo button at the bottom of the list:

Using undo on a Plone web site, as with using undo on computers in general, should be considered as a luxury not to be abused by overuse, as it adds a level of complexity to behind-the-scenes database storage. However, use it when you need it.