%% You should probably cite draft-seantek-windows-image instead of this I-D.
@techreport{seantek-image-wmf-emf-00,
    number =    {draft-seantek-image-wmf-emf-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-seantek-image-wmf-emf/00/},
    author =    {Sean Leonard},
    title =     {{The Windows Metafile and Enhanced Metafile Media Types}},
    pagetotal = 8,
    year =      2014,
    month =     oct,
    day =       17,
    abstract =  {This document registers the image/wmf and image/emf media types for use with Windows Metafile and Enhanced Metafile formats. Originally designed for Microsoft Windows 3.0, these image files are intended to be portable between applications and devices, and may contain both vector and raster graphics.},
}