sign manual
/ˌsʌɪn ˈmanjʊəl/ /ˌsʌɪn ˈmanjʊl/noun
An autograph signature, especially that of the sovereign, serving to authenticate a document.
Origin
Late Middle English. From sign + manual, in sense 1 probably after Middle French seing manuel, signe manuel; compare also post-classical Latin signum manuale, and earlier signum manus.