In rugby, a cap is an honor awarded to a player for appearing in a game at the international level). The term "cap" originated in Rugby, England at Rugby School, where it was used to distinguish players from each other by wearing a specific sort of cap. The practice of awarding a cap to every player in an international match of rugby football and association football was approved in 1886). Although in some sports physical caps may not now always be given, the term cap for an international or other appearance has been retained as an indicator of the number of occasions on which a sportsperson has represented a team in a particular sport).

It is important to note that a scrum cap is a form of headgear used by rugby players to protect the ears in the scrum, which can otherwise suffer injuries leading to the condition commonly known as cauliflower ears. Although scrum caps were originally designed for forwards, they are now worn by players of all positions, even those who do not play in the scrum. However, research has shown that scrum caps offer no significant protection against concussions, and players who wear them may feel more confident on the field, leading to reckless behavior.