A waiver or release is the intentional and voluntary act of relinquishing something, such as a known right to sue a person, educational institution, or organization for an injury. Waivers and releases are commonly used by the sponsor of an event (e.g., a marathon) and schools when competitors, students, faculty, or visitors participate in a private or institution-sponsored activity. The term waiver is sometimes used to refer a document that is signed before any damages actually occur. A release is sometimes used to refer to a document that is executed after an injury has occurred.