The user experience when re-ordering tabs in Revit is less than desireable. If you move the cursor off the small tab area it breaks the tab out to a window (which is fine) but if you happen to do that by accident, then if you go to add it back in by dragging the cursor back up to the line of tabs, it only populates the tab back at the start of the list of tabs. You then have to try and drag it across again without going off the line of tabs. The user should have the ability to put it back up wherever they want (similar to the experience in AutoCAD).
Screencast of issue here as created by Autodesk Support (thanks)
https://knowledge.autodesk.com/community/screencast/d610368f-bb1c-4391-ad79-9a2e9beaf7a4
