# This choice of root elements comes from the 1.0b1 RNG schema at
# http://www.oasis-open.org/docbook/relaxng/1.0b1/index.shtml

start = 
  set
  | setindex
  | book
  | part
  | reference
  | preface
  | chapter
  | appendix
  | article
  | bibliography
  | glossary
  | index
  | refentry
  | sect1
  | sect2
  | sect3
  | sect4
  | sect5
  | section