%% You should probably cite draft-greevenbosch-core-minimum-request-interval instead of this I-D.
@techreport{greevenbosch-core-block-minimum-time-00,
    number =    {draft-greevenbosch-core-block-minimum-time-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-greevenbosch-core-block-minimum-time/00/},
    author =    {Bert Greevenbosch},
    title =     {{CoAP Minimum Block Time}},
    pagetotal = 15,
    year =      2012,
    month =     jul,
    day =       8,
    abstract =  {This document defines an "MinimumBlockTime" option for CoAP, which can be used to negotiate the minimum time between two subsequent block requests. It can be used for overload and congestion control. Note Discussion and suggestions for improvement are requested, and should be sent to core@ietf.org.},
}