Section 49
Conversion of indorsement in blank into indorsement in full
Chapter 4: Of negotiation
The holder of a negotiable instrument indorsed in blank may, without signing his own name, by writing above the indorser’s signature a direction to pay to any other person as indorsee, convert the indorsement in blank into an indorsement in full; and the holder does not thereby incur the responsibility of an 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.