%% You should probably cite rfc5229 instead of this I-D.
@techreport{ietf-sieve-variables-08,
    number =    {draft-ietf-sieve-variables-08},
    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-sieve-variables/08/},
    author =    {Kjetil Torgrim Homme},
    title =     {{Sieve Email Filtering: Variables Extension}},
    pagetotal = 11,
    year =      2005,
    month =     dec,
    day =       20,
    abstract =  {In advanced mail filtering rule sets, it is useful to keep state or configuration details across rules. This document updates the Sieve filtering language (RFC 5228) with an extension to support variables. The extension changes the interpretation of strings, adds an action to store data in variables, and supplies a new test so that the value of a string can be examined. {[}STANDARDS-TRACK{]}},
}