%% You should probably cite rfc4484 instead of this I-D.
@techreport{ietf-sipping-trait-authz-02,
    number =    {draft-ietf-sipping-trait-authz-02},
    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-sipping-trait-authz/02/},
    author =    {Jon Peterson and Douglas Sicker and Hannes Tschofenig and James Polk},
    title =     {{Trait-Based Authorization Requirements for the Session Initiation Protocol (SIP)}},
    pagetotal = 15,
    year =      2006,
    month =     jan,
    day =       27,
    abstract =  {This document lays out a set of requirements related to trait-based authorization for the Session Initiation Protocol (SIP). While some authentication mechanisms are described in the base SIP specification, trait-based authorization provides information used to make policy decisions based on the attributes of a participant in a session. This approach provides a richer framework for authorization, as well as allows greater privacy for users of an identity system. This memo provides information for the Internet community.},
}