Negotiable Instruments Law
Section 122. Renunciation by holder.- The holder may expressly renounce his rights against any party to the instrument before, at, or after its maturity. An absolute and unconditional renunciation of his rights against the principal debtor made at or after the maturity of the instrument discharges the instrument. But a renunciation does not affect the rights of a holder in due course without notice. A renunciation must be in writing, unless the instrument is delivered up to the person primarily liable thereon.