%% You should probably cite draft-ietf-vcarddav-birth-death-extensions instead of this I-D.
@techreport{li-vcarddav-vcard-id-property-extensions-03,
    number =    {draft-li-vcarddav-vcard-id-property-extensions-03},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-li-vcarddav-vcard-id-property-extensions/03/},
    author =    {Kepeng Li and Barry Leiba},
    title =     {{vCard Format Extensions : place of birth, place and date of death}},
    pagetotal = 6,
    year =      2011,
    month =     jul,
    day =       8,
    abstract =  {The base vCard 4.0 specification defines a large number of properties, including date of birth. This specification adds three new properties to vCard 4.0, for place of birth, place of death, and date of death. Note Discussion and suggestions for improvement are requested, and should be sent to vcarddav@ietf.org.},
}