%% You should probably cite rfc8676 instead of this I-D.
@techreport{ietf-softwire-yang-02,
    number =    {draft-ietf-softwire-yang-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-softwire-yang/02/},
    author =    {Qi Sun and Hao Wang and Yong Cui and Ian Farrer and Sladjana Zechlin and Mohamed Boucadair and Rajiv Asati},
    title =     {{A YANG Data Model for IPv4-in-IPv6 Address plus Port Softwires}},
    pagetotal = 41,
    year =      2017,
    month =     oct,
    day =       30,
    abstract =  {This document defines YANG data models for the configuration and operation of IPv4-in-IPv6 softwire Border Relays and Customer Premises Equipment. The model covers the Lightweight 4over6, MAP-E, and MAP-T softwire mechanisms.},
}