\documenttype[boot.dtd]{dtd}
\doctype{dtd}
\dtdref{boot.dtd}
\cmt{Use\brk     \verb{<!}DOCTYPE dtd SYSTEM "boot.dtd"\verb{>}\brk}
\begin{document}
\elt{doctype}{--}{(#PCDATA)}{the name of the document type,
    i.e., the name of the root element (which needs to be defined)}
\elt{dtdref}{--}{(#PCDATA)}{the (unquoted) system resource name
   of the DTD to be used with documents of the type "doctype"; this
   name is only used to generate a comment.
   Example: for this DTD:  doctype = dtd   dtdref = boot.dtd}
\enp{dtd}{elt|enp|ent|empt|cmt}
\enp{tags}{rr|ro|or|oo}
\enp{charr}{spc|cma|per|ltc|gtc|qum|sol|col|scl|quo|lsq|rsq}
\enp{charn}{lbr|rbr|exc|atc|hsh|dol|pct|crt|amp|ast|lpr|rpr|und}
\enp{chare}{lsb|rsb|hyp|eqc|plu|vbr|bsl|tld}
\enp{chara}{\%charr|\%charn|\%chare}
\enp{charh}{rdash}
\enp{chars}{\%chara|\%charh|brk}
\enp{eos}{eos|eoq|eoe}
\empt{(\%eos)}{ends of sentence made by GELLMU}
\empt{(\%chars)}{33 printable, non-alphanumeric}
\empt{(\%tags)}{the tag requirement combinations}
\enp{string}{#PCDATA|\%chars}
\elt{ag0}{rr}{(\%string|\%eos)*}{command argument}
\elt{dtd}{oo}{(preamble, body)}
\elt{preamble}{rr}{(doctype,dtdref,(cmt)*)}{zero or more comments}
\elt{body}{--}{(\%dtd)*}
\elt{elt}{ro}{(ag0,ag0,ag0,(ag0)*)}{element:
             name, tags, defn, comments?}
\elt{enp}{ro}{(ag0,ag0,(ag0)*)}{parameter entity:
             name, defn, comments?}
\elt{ent}{ro}{(ag0,ag0,(ag0)*)}{general entity:
             name, defn, comments?}
\elt{empt}{ro}{(ag0,(ag0)*)}{empty element:
             name, comments?}
\elt{cmt}{rr}{((\%string|\%eos|verb)*)}{comment}
\elt{verb}{rr}{((\%string|\%eos)*)}{inline verbatim, OK in cmt}
\end{document}