%% You should probably cite rfc3506 instead of this I-D.
@techreport{ietf-trade-drt-requirements-04,
    number =    {draft-ietf-trade-drt-requirements-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-trade-drt-requirements/04/},
    author =    {Donald E. Eastlake 3rd and Ko Fujimura},
    title =     {{Requirements and Design for Voucher Trading System (VTS)}},
    pagetotal = 15,
    year =      2002,
    month =     jul,
    day =       25,
    abstract =  {Crediting loyalty points and collecting digital coupons or gift certificates are common functions in purchasing and trading transactions. These activities can be generalized using the concept of a "voucher", which is a digital representation of the right to claim goods or services. This document presents a Voucher Trading System (VTS) that circulates vouchers securely and its terminology; it lists design principles and requirements for VTS and the Generic Voucher Language (GVL), with which diverse types of vouchers can be described. This memo provides information for the Internet community.},
}