%% You should probably cite rfc6723 instead of this I-D.
@techreport{ietf-pwe3-cbit-negotiation-04,
    number =    {draft-ietf-pwe3-cbit-negotiation-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-pwe3-cbit-negotiation/04/},
    author =    {Lizhong Jin and Raymond Key and Simon DeLord and Thomas Nadeau and Sami Boutros},
    title =     {{Pseudowire Control Word Negotiation Mechanism Update}},
    pagetotal = 9,
    year =      2012,
    month =     jun,
    day =       15,
    abstract =  {The control word negotiation mechanism specified in RFC4447 has a problem when PE changes the preference for the use of control word from PREFERRED to NOT-PREFERRED. This draft updates RFC4447 by introducing a message exchanging mechanism to resolve this control word negotiation issue.},
}