map {; $_ => 1} qw( object script map )
  # I've no idea why there's these latter exceptions.
  # I'm just following the HTML4.01 DTD.
);

#from html4 strict:
#<!ENTITY % fontstyle "TT | I | B | BIG | SMALL">
#
#<!ENTITY % phrase "EM | STRONG | DFN | CODE |
#                   SAMP | KBD | VAR | CITE | ABBR | ACRONYM" >
#
#<!ENTITY % special
#   "A | IMG | OBJECT | BR | SCRIPT | MAP | Q | SUB | SUP | SPAN | BDO">
#
#<!ENTITY % formctrl "INPUT | SELECT | TEXTAREA | LABEL | BUTTON">
#
#<!-- %inline; covers inline or "text-level" elements -->
#<!ENTITY % inline "#PCDATA | %fontstyle; | %phrase; | %special; | %formctrl;">

=head2 hashset %HTML::Tagset::isHeadElement

This hashset contains all elements that elements that should be
present only in the 'head' element of an HTML document.

=cut

%isHeadElement = map {; $_ => 1 }
 qw(title base link meta isindex script style object bgsound);

=head2 hashset %HTML::Tagset::isList

This hashset contains all elements that can contain "li" elements.

=cut

%isList         = map {; $_ => 1 } qw(ul ol dir menu);

=head2 hashset %HTML::Tagset::isTableElement

This hashset contains all elements that are to be found only in/under
a "table" element.

=cut

%isTableElement = map {; $_ => 1 }
 qw(tr td th thead tbody tfoot caption col colgroup);

=head2 hashset %HTML::Tagset::isFormElement

This hashset contains all elements that are to be found only in/under
a "form" element.

=cut

%isFormElement  = map {; $_ => 1 }
 qw(input select option optgroup textarea button label);

=head2 hashset %HTML::Tagset::isBodyMarkup

This hashset contains all elements that are to be found only in/under
the "body" element of an HTML document.

=cut

%isBodyElement = map {; $_ => 1 } qw(
  h1 h2 h3 h4 h5 h6
  p div pre plaintext address blockquote
  xmp listing
  center

  multicol
  iframe ilayer nolayer
  bgsound

  hr
  ol ul dir menu li
  dl dt dd
  ins del
  
  fieldset legend
  
  map area
  applet param object
  isindex script noscript
  table
  center
  form
 ),
 keys %isFormElement,
 keys %isPhraseMarkup,   # And everything phrasal
 keys %isTableElement,
;


=head2 hashset %HTML::Tagset::isHeadOrBodyElement

This hashset includes all elements that I notice can fall either in
the head or in the body.

=cut