%% You should probably cite rfc5260 instead of this I-D.
@techreport{freed-sieve-date-index-12,
    number =    {draft-freed-sieve-date-index-12},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-freed-sieve-date-index/12/},
    author =    {Ned Freed},
    title =     {{Sieve Email Filtering: Date and Index Extensions}},
    pagetotal = 13,
    year =      2008,
    month =     may,
    day =       30,
    abstract =  {This document describes the "date" and "index" extensions to the Sieve email filtering language. The "date" extension gives Sieve the ability to test date and time values in various ways. The "index" extension provides a means to limit header and address tests to specific instances of header fields when header fields are repeated. {[}STANDARDS-TRACK{]}},
}