A detailed set of rules and obligations, which all participating broadcasters and participants in the annual Eurovision Song Contest must uphold, is produced annually ahead of each edition of the international song contest. These rules are drafted by the contest organisers, the European Broadcasting Union (EBU), and approved by the contest's reference group. They typically outline which songs may be deemed eligible for entry, the format of the contest, the voting system employed to select a contest winner and how the results of this vote are presented to the televised audience, the overall values of the contest, and distribution and broadcasting rights through television, radio and streaming services.