Clubs are usually attached to a national federation, either directly or through membership of a regional chess association. The national federation in turn is a member of FIDE, the international governing body of chess. This helps to establish uniformity of rules and playing conditions internationally, though some countries such as the United States use their own official set of rules with minor differences from FIDE rules. The United States has many chess clubs affiliated with the United States Chess Federation (USCF). A club's affiliation with its national chess federation helps to standardize chess tournament rules.