Complex sentence: Numerous detailed rules must be observed by the participating nations, and a new version is produced each year, for instance the rules specify various deadlines, including the date by which all the participating broadcasters must submit the final recorded version of their song to the EBU.
Split into simpler sentences: Numerous detailed rules must be observed by the participating nations: a new version is produced each year. For instance the rules specify various deadlines, including the date by which all the participating broadcasters must submit the final recorded version of their song to the EBU.