Horseback Riding and the CCI
The CCI is the international ranking system of three day eventing (a.k.a. combined training). CCI stands for: concours complet internationale. The ranking system is based on stars, CCI* being the lowest level and CCI**** being the highest--the level of Olympics eventing.
Riders and horses must qualify for a CCI**** ranked eventing competition through successful three day event outings at the lower levels. Olympians in eventing are for the most part the top CCI**** riders and horses in their respective countries.
Source: http://www.rk3de.org/eventing.cfm?id=15