Русско-англо-русский юридический словарь

The term signature is generally understood to mean the signing of a written document with one's own hand. (Law Library - American Law and Legal InformationFree Legal Encyclopedia)

Manu propria (Latin for '[signed] with one's own hand'), abbreviated to m.p. or mppria is a phrase sometimes used at the end of typewritten or printed documents when there is no handwritten signature. It is typically found just after the name(s) of the person(s) who would have signed the document if it had not been printed or typewritten. (Wikipedia)

The manuscripts were written in the composer's own hand. (COBUILD Advanced English Dictionary)