Indorsement

noun

1. Superscription; a noting of the contents of any paper on its back; a docketing; briefing.
2. In law, an incidental or subsidiary writing upon the back of a paper, writing, or other document, to the contents of which it relates or pertains.
3. More specifically In commercial law: The signature of the payee of a note, bill, or check, or that of a third person, written on the back of the note or bill in evidence of his transfer of it, or of his assuring its payment, or both.
4. The transfer or assurance so manifested.
5. Ratification; sanction; approval.