Section 15
Indorsement
Chapter 2: Of notes, bills and cheques
When the maker or holder of a negotiable instrument signs the same, otherwise than as such maker, for the purpose of negotiation, on the back or face thereof or on a slip of paper annexed thereto, or so signs for the same purpose a stamped paper intended to be completed as a negotiable instrument, he is said to indorse the same, and is called the “indorser”.
The Negotiable Instruments Act, 1881 (Act No. 26 of 1881). From the updated text on India Code, with later amendments. Being checked against the official copy; amendment notes are not shown yet.