This allows users to add relative URLs to an existing tracker. This is useful for adjusting the channel of the link, such specific sport pages without needing to create a new tracker.
This is not the same as common &redirectURL additions, which allows any URL to be used and redirected but instead allows subpages of the existing domain.
Example:
https://EXAMPLE.servclick1move.com/?mid=12345_1395807&relativepath=ar/game/plinko-v2
In the above example, the original campaign of Homepage AR will instead go to Plinko game on the brand.