%% You should probably cite rfc7265 instead of this I-D.
@techreport{ietf-jcardcal-jcal-04,
    number =    {draft-ietf-jcardcal-jcal-04},
    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-jcardcal-jcal/04/},
    author =    {Philipp Kewisch and Cyrus Daboo and Mike Douglass},
    title =     {{jCal: The JSON format for iCalendar}},
    pagetotal = 31,
    year =      2013,
    month =     jun,
    day =       10,
    abstract =  {This specification defines "jCal", a JSON format for iCalendar data.},
}