%% You should probably cite rfc4791 instead of this I-D.
@techreport{dusseault-caldav-15,
    number =    {draft-dusseault-caldav-15},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-dusseault-caldav/15/},
    author =    {Cyrus Daboo and Lisa M. Dusseault and Bernard Desruisseaux},
    title =     {{Calendaring Extensions to WebDAV (CalDAV)}},
    pagetotal = 107,
    year =      2006,
    month =     sep,
    day =       15,
    abstract =  {This document defines extensions to the Web Distributed Authoring and Versioning (WebDAV) protocol to specify a standard way of accessing, managing, and sharing calendaring and scheduling information based on the iCalendar format. This document defines the "calendar-access" feature of CalDAV. {[}STANDARDS-TRACK{]}},
}