%% You should probably cite draft-ietf-pim-hierarchicaljoinattr instead of this I-D.
@techreport{venaas-pim-hierarchicaljoinattr-00,
    number =    {draft-venaas-pim-hierarchicaljoinattr-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-venaas-pim-hierarchicaljoinattr/00/},
    author =    {Stig Venaas and Isidor Kouvelas and Jesus Arango},
    title =     {{Hierarchical Join/Prune Attributes}},
    pagetotal = 14,
    year =      2013,
    month =     feb,
    day =       6,
    abstract =  {This document defines a hierachical method of encoding Join attributes, providing a more efficient encoding when the same attribute values need to be specified for multiple sources in a PIM Join/Prune message.},
}