Examples:

  Entity ref                    Equivalent tag
  -------------------------     ------------------------------
  &dtml-foo;	                <dtml-var foo html_quote>
  &dtml.url_quote-foo           <dtml-var foo url_quote>
  &dtml.url_quote.upper-foo     <dtml-var foo url_quote upper>
  &dtml.-foo                    <dtml-var foo>
  -------------------------     ------------------------------