Complex sentence: An International Federation (IF) is responsible for ensuring that the sport's activities follow the Olympic Charter; from the moment their sport is recognized they become official Olympic federations and can assemble with the IOC and remaining Olympic IFs.
Split into simpler sentences: An International Federation (IF) is responsible for ensuring that the sport's activities follow the Olympic Charter. From the moment their sport is recognized they become official Olympic federations and can assemble with the IOC and remaining Olympic IFs.