%% You should probably cite rfc2083 instead of this I-D.
@techreport{boutell-png-spec-04,
    number =    {draft-boutell-png-spec-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-boutell-png-spec/04/},
    author =    {Thomas Boutell},
    title =     {{PNG (Portable Network Graphics) Specification Version 1.0}},
    pagetotal = 102,
    year =      1996,
    month =     jun,
    day =       11,
    abstract =  {This document describes PNG (Portable Network Graphics), an extensible file format for the lossless, portable, well-compressed storage of raster images. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.},
}