allonge

noun | \ ə-ˈlänj, a-ˈlȯⁿzh \ | al·longe

1. : a paper attached to an instrument to provide space for additional endorsements : rider

   Note: Under Uniform Commercial Code section 3-204(a), an allonge must be so firmly affixed to the instrument that it becomes part of it in order for the endorsements to be valid. Endorsements on an allonge are considered invalid if there is still room on the instrument for endorsements.