URL or Element is Active -Yes or No

You can set any URL or Element in your tests as 

Active : Yes/No 

If set to "YES" it will be shown in the rotation.
If set to "NO"  it will not appear in the rotation and will be skipped.  

HOWEVER - if a winner has been chosen, this overrides this setting.  So, let's say in an Auto-Optimizer test, URL 2 has already been set as winner because the test has completed/you have manually selected it.  If you now try to mark URL 2 as inactive, it will STILL be shown because it is the winner.