This glossary serves as a point of reference for terms which are commonly used within association football, and which have a sport-specific meaning. It seeks to avoid defining common English words and phrases that have no special meaning within football. Exceptions include cases where a word or phrase's use in the context of football might cause confusion to someone not familiar with the sport (such as clean sheet), or where it is fundamental to understanding the sport (such as goal). Entries on nicknames relating to specific players or teams are actively avoided. Other phrases without entries are specific clubs, rivalries, media organisations or works, unless the name also has a more general meaning within football, as is the case with El Clásico and Roy of the Rovers stuff.