Using these tools
You can use these tools any time. Simply press the Set View Extent Bookmark tool whenever you want to
record the current extent of the map window (a.k.a. view), and press the Zoom To View Extent Bookmark
whenever you want to return to that extent. This tool does not affect any of the standard ArcMap tools
like Zoom To Full Extent, or Zoom To Selected Layer. If you press the Zoom To View Extent Bookmark tool
when you have not set a bookmark, nothing will happen (no error message).