%% You should probably cite draft-ietf-bier-bierin6 instead of this I-D.
@techreport{zhang-bier-bierin6-09,
    number =    {draft-zhang-bier-bierin6-09},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-zhang-bier-bierin6/09/},
    author =    {Zheng Zhang and Zhaohui (Jeffrey) Zhang and IJsbrand Wijnands and Mankamana Prasad Mishra and Hooman Bidgoli and Gyan Mishra},
    title =     {{Supporting BIER in IPv6 Networks (BIERin6)}},
    pagetotal = 11,
    year =      2021,
    month =     feb,
    day =       22,
    abstract =  {BIER is a new architecture for the forwarding of multicast data packets without requiring per-flow state inside the network. This document describes how the existing BIER encapsulation specified in RFC 8296 works in an IPv6 non-MPLS network, referred to as BIERin6. Specifically, like in an IPv4 network, BIER can work over L2 links directly or over tunnels. In case of IPv6 tunneling, a new IP "Next Header" type is to be assigned for BIER.},
}