%% You should probably cite draft-ietf-acme-subdomains instead of this I-D.
@techreport{friel-acme-subdomains-02,
    number =    {draft-friel-acme-subdomains-02},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-friel-acme-subdomains/02/},
    author =    {Owen Friel and Richard Barnes and Tim Hollebeek and Michael Richardson},
    title =     {{ACME for Subdomains}},
    pagetotal = 11,
    year =      2020,
    month =     mar,
    day =       7,
    abstract =  {This document outlines how ACME can be used by a client to obtain a certificate for a subdomain identifier from a certificate authority. The client has fulfilled a challenge against a parent domain but does not need to fulfil a challenge against the explicit subdomain as certificate authority policy allows issuance of the subdomain certificate without explicit subdomain ownership proof.},
}