Olympic sports are governed by international sports federations (IFs) recognised by the IOC as the global supervisors of those sports. There are 35 federations represented at the IOC. There are sports recognised by the IOC that are not included in the Olympic programme. These sports are not considered Olympic sports, but they can be promoted to this status during a programme revision that occurs in the first IOC session following a celebration of the Olympic Games. During such revisions, sports can be excluded or included in the programme on the basis of a two-thirds majority vote of the members of the IOC. There are recognised sports that have never been on an Olympic programme in any capacity, including chess and surfing.