The challenge is that you have to be an experienced cacher who has found at least 1.000 caches with either D-rating or T-rating (or both) being 2,0 or higher.
Myself as owner I have fulfilled the requirement with 2.642 qualified caches found (as of Jan 07, 2017).
The D-rating of this challenge refers to the requirement, the T-rating refers to the actual hide-out.