This Challenge cache is all about those prolific cache-placing COs, and of course the finders of their caches.
To be able to log this Challenge cache as a find you must have found at least 100 caches by 10 separate cache placers/COs, and, for one of those 10 COs you must have found at least a 1000 caches of theirs.
So, the minimum qualifying cache amount will be 1900, many will have more. Caches found in any country in the world count, just a minimum of 100 finds per CO
To show that you qualify please make a list of your top 10 finds by owner, this list can be found on Project-gc.com, on the Finds tab, at the bottom, 'Finds by owner'.
or use this handy checker kindly produced by the Seagnoid.

I myself recently qualified for this Challenge, hence me listing it now as a challenge for others.
My top 10 list looks like this;
1 - bumandworker Finds 1160
2 - skindo 207
3 - the Seagnoid 204
4 - GH6710 120
5 - Sidewaze 119
6 - SoBad 118
7 - BigglesNZ 110
8 - gracie7 + Mum 106
9 - TheWanglers 104
10- Marisa&Caleb 104
Cache is a magnetic mint tin with logbook only. Being a prolific finder you won't need telling to BYOP, surely?