To become and to maintain your RKC credentials you need to be able to demonstrate competency in the core KB lifts (Swing, Clean, Snatch, TGU, etc.) as well as do a little something called the 05 Minute Snatch Test. It's simple really - all you have to do is snatch a 53# KB 100 times in 05 minutes. That works out to 20 snatches a minute or one snatch every 03 seconds. It's not a lot of fun but it's not supposed to be - essentially it's a gut-check to see how hard you are willing to push yourself.
BTW - there are a lot of protocols floating around on how to get to this volume of snatches prior to the RKC. The best one is to train at this level (or above) all of the time so that you won't need to prepare for the test!