SLICE:
Content Model Declaration

Content Rule

((p|heading|listing|itemize|enumerate|tabular|img|video|
  slide-show|sql|flowbox|frame|button|next-button|previous-button|
  back-button|hyperlink|input|scribble|pop-up|browser|
  multiple-browser|radio-button|checkbox|pull-down|
  vertical-slider|horizontal-slider|window|page|demo|
  registration-form|question-form|search-form|shopping-bag|
  shopping-list|table-of-contents|open|redraw|suspend|close|next|
  previous|up|down|back|additional|exit|audio|applet|set|empty|
  non-empty|foreach|order|time-line|on-end-of)+|
 (par)+)