Unique Traverse Settings are new with TPC Desktop 2008. They allow you to modify the Traverse Settings for any traverse in any drawing without affecting the Traverse Settings for that traverse in any other drawing. Unique Traverse Settings provide greater flexibility in creating your drawings via the traverses.
In previous versions, users would some times make a copy of a traverse and tag the original traverse in one drawing and the copy in another drawing. This way the traverse could look different in each drawing. Unique Traverse Settings accomplish this without the need to create a copy of a traverse.
Because you told TPC these are unique Traverse Settings, they are stored with the drawing, not the traverse. The drawing remembers that this traverse has unique Traverse Settngs, so if you access the Traverse Settings for this traverse either from the Traverses Manager or the drawing you will get the unique Traverse Settings.
The bottom left corner of the Control, Side Shot and Lot Label dialogs displays the message 'These settings are unique to this drawing' to indicate when you are working with unique Traverse Settings.
Unique Traverse Settings are not stored for later use when they are canceled. They are just gone. If you wanted to use unique Traverse Settings again, you would have to re-select the settings you want then make them unique.
The Advanced tab currently gives you options for managing unique Traverse Settings. Besides canceling the unique settings, you can modify the traverse settings plus update all the drawings that use this traverse. The Advanced tab explains these options more fully.