%% You should probably cite draft-ietf-6man-ug instead of this I-D.
@techreport{carpenter-6man-ug-01,
    number =    {draft-carpenter-6man-ug-01},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-carpenter-6man-ug/01/},
    author =    {Brian E. Carpenter and Sheng Jiang},
    title =     {{The U and G bits in IPv6 Interface Identifiers}},
    pagetotal = 9,
    year =      2013,
    month =     feb,
    day =       21,
    abstract =  {The IPv6 addressing architecture defines a method by which the Universal and Group bits of an IEEE link-layer address are mapped into an IPv6 unicast interface identifier. This document clarifies the status of those bits for interface identifiers that are not derived from an IEEE link-layer address, and updates RFC 4291 accordingly.},
}