@techreport{seantek-constrained-abnf-02,
    number =    {draft-seantek-constrained-abnf-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-seantek-constrained-abnf/02/},
    author =    {Sean Leonard and Paul Kyzivat},
    title =     {{Constrained ABNF}},
    pagetotal = 7,
    year =      2017,
    month =     mar,
    day =       13,
    abstract =  {This document extends the base definition of ABNF (Augmented Backus- Naur Form) to express a rule that is constrained by another rule. If a rule B is constrained by rule A, then every production generated by rule B must also be generated by rule A. By creating subordinate production forms, ABNF-using specifications can formally denote the relationship between a general rule and specific subsets of that rule, while preserving ABNF's context-free nature.},
}