Binary package “docbook-ebnf” in ubuntu jammy
EBNF module for the XML version of the DocBook DTD
DocBook is a general-purpose and modular SGML and XML Document-Type
Definition. This is a module that adds elements for the markup of
EBNF grammar rules to DocBook.
.
It is fully documented in "DocBook - The Definitive Guide", available
in the docbook-defguide package.