Extensible HTML version 1.0 Strict DTD

• This is the same as HTML 4 Strict except for changes due to the differences between XML and SGML. Namespace = http://www.w3.org/1999/xhtml For further information, see: http://www.w3.org/TR/xhtml1 Copyright (c) 1998-2002 W3C (MIT, INRIA, Keio), All Rights Reserved. This DTD module is identified by the PUBLIC and SYSTEM identifiers: PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" SYSTEM "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd" $Revision: 1.1 $ $Date: 2002/08/01 13:56:03 $

• Character mnemonic entities
• Imported Names
• Generic Attributes
• Text Elements
• Block level elements
• Content models for exclusions
• Document Structure
• Document Head
• Document Body
• Paragraphs
• Headings
• Lists
• Address
• Horizontal Rule
• Preformatted Text
• Block-like Quotes
• Inserted/Deleted Text
• The Anchor Element
• Inline Elements
• Object
• Images
• Client-side image maps
• Forms
• Tables

topCharacter mnemonic entities

• <!ENTITY% HTMLlat1 PUBLIC "-//W3C//ENTITIES Latin 1 for XHTML//EN" "xhtml-lat1.ent">
• %HTMLlat1;
• <!ENTITY% HTMLsymbol PUBLIC "-//W3C//ENTITIES Symbols for XHTML//EN" "xhtml-symbol.ent">
• %HTMLsymbol;
• <!ENTITY% HTMLspecial PUBLIC "-//W3C//ENTITIES Special for XHTML//EN" "xhtml-special.ent">
• %HTMLspecial;

topImported Names

• <!ENTITY% ContentType "CDATA">
• media type, as per [RFC2045]
• <!ENTITY% ContentTypes "CDATA">
• comma-separated list of media types, as per [RFC2045]
• <!ENTITY% Charset "CDATA">
• a character encoding, as per [RFC2045]
• <!ENTITY% Charsets "CDATA">
• a space separated list of character encodings, as per [RFC2045]
• <!ENTITY% LanguageCode "NMTOKEN">
• a language code, as per [RFC3066]
• <!ENTITY% Character "CDATA">
• a single character, as per section 2.2 of [XML]
• <!ENTITY% Number "CDATA">
• one or more digits
• <!ENTITY% LinkTypes "CDATA">
• space-separated list of link types
• <!ENTITY% MediaDesc "CDATA">
• single or comma-separated list of media descriptors
• <!ENTITY% URI "CDATA">
• a Uniform Resource Identifier, see [RFC2396]
• <!ENTITY% UriList "CDATA">
• a space separated list of Uniform Resource Identifiers
• <!ENTITY% Datetime "CDATA">
• date and time information. ISO date format
• <!ENTITY% Script "CDATA">
• script expression
• <!ENTITY% StyleSheet "CDATA">
• style sheet data
• <!ENTITY% Text "CDATA">
• used for titles etc.
• <!ENTITY% Length "CDATA">
• nn for pixels or nn% for percentage length
• <!ENTITY% MultiLength "CDATA">
• pixel, percentage, or relative
• <!ENTITY% Pixels "CDATA">
• integer representing length in pixels
• these are used for image maps
• <!ENTITY% Shape "(rect|circle|poly|default)" >
• <!ENTITY% Coords "CDATA">
• comma separated list of lengths

topGeneric Attributes

• core attributes common to most elements
  id	document-wide unique id
  class	space separated list of classes
  style	associated style info
  title	advisory title/amplification

• <!ENTITY% coreattrs
  "id	ID	#IMPLIED
  class	CDATA	#IMPLIED
  style	%StyleSheet;	#IMPLIED
  title	%Text;	#IMPLIED"
  >

• internationalization attributes
  lang	language code (backwards compatible)
  xml:lang	language code (as per XML 1.0 spec)
  dir	direction for weak/neutral text

• <!ENTITY% i18n
  "lang	%LanguageCode;	#IMPLIED
  xml:lang	%LanguageCode;	#IMPLIED
  dir	(ltr|rtl)	#IMPLIED"
  >

• attributes for common UI events
  onclick	a pointer button was clicked
  ondblclick	a pointer button was double clicked
  onmousedown	a pointer button was pressed down
  onmouseup	a pointer button was released
  onmousemove	a pointer was moved onto the element
  onmouseout	a pointer was moved away from the element
  onkeypress	a key was pressed and released
  onkeydown	a key was pressed down
  onkeyup	a key was released

• <!ENTITY% events
  "onclick	%Script;	#IMPLIED
  ondblclick	%Script;	#IMPLIED
  onmousedown	%Script;	#IMPLIED
  onmouseup	%Script;	#IMPLIED
  onmouseover	%Script;	#IMPLIED
  onmousemove	%Script;	#IMPLIED
  onmouseout	%Script;	#IMPLIED
  onkeypress	%Script;	#IMPLIED
  onkeydown	%Script;	#IMPLIED
  onkeyup	%Script;	#IMPLIED"
  >

• attributes for elements that can get the focus
  accesskey	accessibility key character
  tabindex	position in tabbing order
  onfocus	the element got the focus
  onblur	the element lost the focus

• <!ENTITY% focus
  "accesskey	%Character;	#IMPLIED
  tabindex	%Number;	#IMPLIED
  onfocus	%Script;	#IMPLIED
  onblur	%Script;	#IMPLIED"
  >

• <!ENTITY% attrs "%coreattrs; %i18n; %events;">

topText Elements

• <!ENTITY% special.pre "br | span | bdo | map">
• <!ENTITY% special "%special.pre; | object | img ">
• <!ENTITY% fontstyle "tt | i | b | big | small ">
• <!ENTITY% phrase "em | strong | dfn | code | q | samp | kbd | var | cite | abbr | acronym | sub | sup ">
• <!ENTITY% inline.forms "input | select | textarea | label | button">
• these can occur at block or inline level
• <!ENTITY% misc.inline "ins | del | script">
• these can only occur at block level
• <!ENTITY% misc "noscript | %misc.inline;">
• <!ENTITY% inline "a | %special; | %fontstyle; | %phrase; | %inline.forms;">
• %Inline; covers inline or "text-level" elements
• <!ENTITY% Inline "(#PCDATA | %inline; | %misc.inline;)*">

topBlock level elements

• <!ENTITY% heading "h1|h2|h3|h4|h5|h6">
• <!ENTITY% lists "ul | ol | dl">
• <!ENTITY% blocktext "pre | hr | blockquote | address">
• <!ENTITY% block "p | %heading; | div | %lists; | %blocktext; | fieldset | table">
• <!ENTITY% Block "(%block; | form | %misc;)*">
• %Flow; mixes block and inline and is used for list items etc.
• <!ENTITY% Flow "(#PCDATA | %block; | form | %inline; | %misc;)*">

topContent models for exclusions

• a elements use %Inline; excluding a
• <!ENTITY% a.content "(#PCDATA | %special; | %fontstyle; | %phrase; | %inline.forms; | %misc.inline;)*">
• pre uses %Inline excluding big, small, sup or sup
• <!ENTITY% pre.content "(#PCDATA | a | %fontstyle; | %phrase; | %special.pre; | %misc.inline; | %inline.forms;)*">
• form uses %Block; excluding form
• <!ENTITY% form.content "(%block; | %misc;)*">
• button uses %Flow; but excludes a, form and form controls
• <!ENTITY% button.content "(#PCDATA | p | %heading; | div | %lists; | %blocktext; | table | %special; | %fontstyle; | %phrase; | %misc;)*">

topDocument Structure

• the namespace URI designates the document profile
• <!ELEMENThtml (head, body)>

• <!ATTLISThtml
  %i18n;
  id	ID	#IMPLIED
  xmlns	%URI;	#FIXED 'http://www.w3.org/1999/xhtml'
  >

topDocument Head

• <!ENTITY% head.misc "(script|style|meta|link|object)*">
• content model is %head.misc; combined with a single title and an optional base element in any order
• <!ELEMENThead ( %head.misc;, ( (title, %head.misc;, (base, %head.misc;)?) | (base, %head.misc;, (title, %head.misc;)) ) ) >

• <!ATTLISThead
  %i18n;
  id	ID	#IMPLIED
  profile	%URI;	#IMPLIED
  >

• The title element is not considered part of the flow of text. It should be displayed, for example as the page header or window title. Exactly one title is required per document.
• <!ELEMENTtitle (#PCDATA)>
• <!ATTLISTtitle %i18n; id ID #IMPLIED >
• document base URI
• <!ELEMENTbase EMPTY>

• <!ATTLISTbase
  href	%URI;	#REQUIRED
  id	ID	#IMPLIED
  >

• generic metainformation
• <!ELEMENTmeta EMPTY>

• <!ATTLISTmeta
  %i18n;
  id	ID	#IMPLIED
  http-equiv	CDATA	#IMPLIED
  name	CDATA	#IMPLIED
  content	CDATA	#REQUIRED
  scheme	CDATA	#IMPLIED
  >

• Relationship values can be used in principle: a) for document specific toolbars/menus when used with the link element in document head e.g. start, contents, previous, next, index, end, help b) to link to a separate style sheet (rel="stylesheet") c) to make a link to a script (rel="script") d) by stylesheets to control how collections of html nodes are rendered into printed documents e) to make a link to a printable version of this document e.g. a PostScript or PDF version (rel="alternate" media="print")
• <!ELEMENTlink EMPTY>

• <!ATTLISTlink
  %attrs;
  charset	%Charset;	#IMPLIED
  href	%URI;	#IMPLIED
  hreflang	%LanguageCode;	#IMPLIED
  type	%ContentType;	#IMPLIED
  rel	%LinkTypes;	#IMPLIED
  rev	%LinkTypes;	#IMPLIED
  media	%MediaDesc;	#IMPLIED
  >

• style info, which may include CDATA sections
• <!ELEMENTstyle (#PCDATA)>

• <!ATTLISTstyle
  %i18n;
  id	ID	#IMPLIED
  type	%ContentType;	#REQUIRED
  media	%MediaDesc;	#IMPLIED
  title	%Text;	#IMPLIED
  xml:space	(preserve)	#FIXED 'preserve'
  >

• script statements, which may include CDATA sections
• <!ELEMENTscript (#PCDATA)>

• <!ATTLISTscript
  id	ID	#IMPLIED
  charset	%Charset;	#IMPLIED
  type	%ContentType;	#REQUIRED
  src	%URI;	#IMPLIED
  defer	(defer)	#IMPLIED
  xml:space	(preserve)	#FIXED 'preserve'
  >

• alternate content container for non script-based rendering
• <!ELEMENTnoscript %Block;>
• <!ATTLISTnoscript %attrs; >

topDocument Body

• <!ELEMENTbody %Block;>

• <!ATTLISTbody
  %attrs;
  onload	%Script;	#IMPLIED
  onunload	%Script;	#IMPLIED
  >

• <!ELEMENTdiv %Flow;>
• generic language/style container
• <!ATTLISTdiv %attrs; >

topParagraphs

• <!ELEMENTp %Inline;>
• <!ATTLISTp %attrs; >

topHeadings

• There are six levels of headings from h1 (the most important) to h6 (the least important).
• <!ELEMENTh1 %Inline;>
• <!ATTLISTh1 %attrs; >
• <!ELEMENTh2 %Inline;>
• <!ATTLISTh2 %attrs; >
• <!ELEMENTh3 %Inline;>
• <!ATTLISTh3 %attrs; >
• <!ELEMENTh4 %Inline;>
• <!ATTLISTh4 %attrs; >
• <!ELEMENTh5 %Inline;>
• <!ATTLISTh5 %attrs; >
• <!ELEMENTh6 %Inline;>
• <!ATTLISTh6 %attrs; >

topLists

• Unordered list
• <!ELEMENTul (li)+>
• <!ATTLISTul %attrs; >
• Ordered (numbered) list
• <!ELEMENTol (li)+>
• <!ATTLISTol %attrs; >
• list item
• <!ELEMENTli %Flow;>
• <!ATTLISTli %attrs; >
• definition lists - dt for term, dd for its definition
• <!ELEMENTdl (dt|dd)+>
• <!ATTLISTdl %attrs; >
• <!ELEMENTdt %Inline;>
• <!ATTLISTdt %attrs; >
• <!ELEMENTdd %Flow;>
• <!ATTLISTdd %attrs; >

topAddress

• information on author
• <!ELEMENTaddress %Inline;>
• <!ATTLISTaddress %attrs; >

topHorizontal Rule

• <!ELEMENThr EMPTY>
• <!ATTLISThr %attrs; >

topPreformatted Text

• content is %Inline; excluding "img|object|big|small|sub|sup"
• <!ELEMENTpre %pre.content;>
• <!ATTLISTpre %attrs; xml:space (preserve) #FIXED 'preserve' >

topBlock-like Quotes

• <!ELEMENTblockquote %Block;>
• <!ATTLISTblockquote %attrs; cite %URI; #IMPLIED >

topInserted/Deleted Text

• ins/del are allowed in block and inline content, but its inappropriate to include block content within an ins element occurring in inline content.
• <!ELEMENTins %Flow;>

• <!ATTLISTins
  %attrs;
  cite	%URI;	#IMPLIED
  datetime	%Datetime;	#IMPLIED
  >

• <!ELEMENTdel %Flow;>

• <!ATTLISTdel
  %attrs;
  cite	%URI;	#IMPLIED
  datetime	%Datetime;	#IMPLIED
  >

topThe Anchor Element

• content is %Inline; except that anchors shouldn't be nested
• <!ELEMENTa %a.content;>

• <!ATTLISTa
  %attrs;
  %focus;
  charset	%Charset;	#IMPLIED
  type	%ContentType;	#IMPLIED
  name	NMTOKEN	#IMPLIED
  href	%URI;	#IMPLIED
  hreflang	%LanguageCode;	#IMPLIED
  rel	%LinkTypes;	#IMPLIED
  rev	%LinkTypes;	#IMPLIED
  shape	%Shape;	"rect"
  coords	%Coords;	#IMPLIED
  >

topInline Elements

• <!ELEMENTspan %Inline;>
• generic language/style container
• <!ATTLISTspan %attrs; >
• <!ELEMENTbdo %Inline;>
• I18N BiDi over-ride

• <!ATTLISTbdo
  %coreattrs;
  %events;
  lang	%LanguageCode;	#IMPLIED
  xml:lang	%LanguageCode;	#IMPLIED
  dir	(ltr|rtl)	#REQUIRED
  >

• <!ELEMENTbr EMPTY>
• forced line break
• <!ATTLISTbr %coreattrs; >
• <!ELEMENTem %Inline;>
• emphasis
• <!ATTLISTem %attrs;>
• <!ELEMENTstrong %Inline;>
• strong emphasis
• <!ATTLISTstrong %attrs;>
• <!ELEMENTdfn %Inline;>
• definitional
• <!ATTLISTdfn %attrs;>
• <!ELEMENTcode %Inline;>
• program code
• <!ATTLISTcode %attrs;>
• <!ELEMENTsamp %Inline;>
• sample
• <!ATTLISTsamp %attrs;>
• <!ELEMENTkbd %Inline;>
• something user would type
• <!ATTLISTkbd %attrs;>
• <!ELEMENTvar %Inline;>
• variable
• <!ATTLISTvar %attrs;>
• <!ELEMENTcite %Inline;>
• citation
• <!ATTLISTcite %attrs;>
• <!ELEMENTabbr %Inline;>
• abbreviation
• <!ATTLISTabbr %attrs;>
• <!ELEMENTacronym %Inline;>
• acronym
• <!ATTLISTacronym %attrs;>
• <!ELEMENTq %Inline;>
• inlined quote
• <!ATTLISTq %attrs; cite %URI; #IMPLIED >
• <!ELEMENTsub %Inline;>
• subscript
• <!ATTLISTsub %attrs;>
• <!ELEMENTsup %Inline;>
• superscript
• <!ATTLISTsup %attrs;>
• <!ELEMENTtt %Inline;>
• fixed pitch font
• <!ATTLISTtt %attrs;>
• <!ELEMENTi %Inline;>
• italic font
• <!ATTLISTi %attrs;>
• <!ELEMENTb %Inline;>
• bold font
• <!ATTLISTb %attrs;>
• <!ELEMENTbig %Inline;>
• bigger font
• <!ATTLISTbig %attrs;>
• <!ELEMENTsmall %Inline;>
• smaller font
• <!ATTLISTsmall %attrs;>

topObject

• object is used to embed objects as part of HTML pages. param elements should precede other content. Parameters can also be expressed as attribute/value pairs on the object element itself when brevity is desired.
• <!ELEMENTobject (#PCDATA | param | %block; | form | %inline; | %misc;)*>

• <!ATTLISTobject
  %attrs;
  declare	(declare)	#IMPLIED
  classid	%URI;	#IMPLIED
  codebase	%URI;	#IMPLIED
  data	%URI;	#IMPLIED
  type	%ContentType;	#IMPLIED
  codetype	%ContentType;	#IMPLIED
  archive	%UriList;	#IMPLIED
  standby	%Text;	#IMPLIED
  height	%Length;	#IMPLIED
  width	%Length;	#IMPLIED
  usemap	%URI;	#IMPLIED
  name	NMTOKEN	#IMPLIED
  tabindex	%Number;	#IMPLIED
  >

• param is used to supply a named property value. In XML it would seem natural to follow RDF and support an abbreviated syntax where the param elements are replaced by attribute value pairs on the object start tag.
• <!ELEMENTparam EMPTY>

• <!ATTLISTparam
  id	ID	#IMPLIED
  name	CDATA	#IMPLIED
  value	CDATA	#IMPLIED
  valuetype	(data|ref|object)	"data"
  type	%ContentType;	#IMPLIED
  >

topImages

• To avoid accessibility problems for people who aren't able to see the image, you should provide a text description using the alt and longdesc attributes. In addition, avoid the use of server-side image maps. Note that in this DTD there is no name attribute. That is only available in the transitional and frameset DTD.
• <!ELEMENTimg EMPTY>

• <!ATTLISTimg
  %attrs;
  src	%URI;	#REQUIRED
  alt	%Text;	#REQUIRED
  longdesc	%URI;	#IMPLIED
  height	%Length;	#IMPLIED
  width	%Length;	#IMPLIED
  usemap	%URI;	#IMPLIED
  ismap	(ismap)	#IMPLIED
  >

• usemap points to a map element which may be in this document or an external document, although the latter is not widely supported

topClient-side image maps

• These can be placed in the same document or grouped in a separate document although this isn't yet widely supported
• <!ELEMENTmap ((%block; | form | %misc;)+ | area+)>

• <!ATTLISTmap
  %i18n;
  %events;
  id	ID	#REQUIRED
  class	CDATA	#IMPLIED
  style	%StyleSheet;	#IMPLIED
  title	%Text;	#IMPLIED
  name	NMTOKEN	#IMPLIED
  >

• <!ELEMENTarea EMPTY>

• <!ATTLISTarea
  %attrs;
  %focus;
  shape	%Shape;	"rect"
  coords	%Coords;	#IMPLIED
  href	%URI;	#IMPLIED
  nohref	(nohref)	#IMPLIED
  alt	%Text;	#REQUIRED
  >

topForms

• <!ELEMENTform %form.content;>
• forms shouldn't be nested

• <!ATTLISTform
  %attrs;
  action	%URI;	#REQUIRED
  method	(get|post)	"get"
  enctype	%ContentType;	"application/x-www-form-urlencoded"
  onsubmit	%Script;	#IMPLIED
  onreset	%Script;	#IMPLIED
  accept	%ContentTypes;	#IMPLIED
  accept-charset	%Charsets;	#IMPLIED
  >

• Each label must not contain more than ONE field Label elements shouldn't be nested.
• <!ELEMENTlabel %Inline;>

• <!ATTLISTlabel
  %attrs;
  for	IDREF	#IMPLIED
  accesskey	%Character;	#IMPLIED
  onfocus	%Script;	#IMPLIED
  onblur	%Script;	#IMPLIED
  >

• <!ENTITY% InputType "(text | password | checkbox | radio | submit | reset | file | hidden | image | button)" >
• the name attribute is required for all but submit & reset
• <!ELEMENTinput EMPTY>
• form control

• <!ATTLISTinput
  %attrs;
  %focus;
  type	%InputType;	"text"
  name	CDATA	#IMPLIED
  value	CDATA	#IMPLIED
  checked	(checked)	#IMPLIED
  disabled	(disabled)	#IMPLIED
  readonly	(readonly)	#IMPLIED
  size	CDATA	#IMPLIED
  maxlength	%Number;	#IMPLIED
  src	%URI;	#IMPLIED
  alt	CDATA	#IMPLIED
  usemap	%URI;	#IMPLIED
  onselect	%Script;	#IMPLIED
  onchange	%Script;	#IMPLIED
  accept	%ContentTypes;	#IMPLIED
  >

• <!ELEMENTselect (optgroup|option)+>
• option selector

• <!ATTLISTselect
  %attrs;
  name	CDATA	#IMPLIED
  size	%Number;	#IMPLIED
  multiple	(multiple)	#IMPLIED
  disabled	(disabled)	#IMPLIED
  tabindex	%Number;	#IMPLIED
  onfocus	%Script;	#IMPLIED
  onblur	%Script;	#IMPLIED
  onchange	%Script;	#IMPLIED
  >

• <!ELEMENToptgroup (option)+>
• option group

• <!ATTLISToptgroup
  %attrs;
  disabled	(disabled)	#IMPLIED
  label	%Text;	#REQUIRED
  >

• <!ELEMENToption (#PCDATA)>
• selectable choice

• <!ATTLISToption
  %attrs;
  selected	(selected)	#IMPLIED
  disabled	(disabled)	#IMPLIED
  label	%Text;	#IMPLIED
  value	CDATA	#IMPLIED
  >

• <!ELEMENTtextarea (#PCDATA)>
• multi-line text field

• <!ATTLISTtextarea
  %attrs;
  %focus;
  name	CDATA	#IMPLIED
  rows	%Number;	#REQUIRED
  cols	%Number;	#REQUIRED
  disabled	(disabled)	#IMPLIED
  readonly	(readonly)	#IMPLIED
  onselect	%Script;	#IMPLIED
  onchange	%Script;	#IMPLIED
  >

• The fieldset element is used to group form fields. Only one legend element should occur in the content and if present should only be preceded by whitespace.
• <!ELEMENTfieldset (#PCDATA | legend | %block; | form | %inline; | %misc;)*>
• <!ATTLISTfieldset %attrs; >
• <!ELEMENTlegend %Inline;>
• fieldset label
• <!ATTLISTlegend %attrs; accesskey %Character; #IMPLIED >
• Content is %Flow; excluding a, form and form controls
• <!ELEMENTbutton %button.content;>
• push button

• <!ATTLISTbutton
  %attrs;
  %focus;
  name	CDATA	#IMPLIED
  value	CDATA	#IMPLIED
  type	(button|submit|reset)	"submit"
  disabled	(disabled)	#IMPLIED
  >

topTables

• Derived from IETF HTML table standard, see [RFC1942]
• The border attribute sets the thickness of the frame around the table. The default units are screen pixels. The frame attribute specifies which parts of the frame around the table should be rendered. The values are not the same as CALS to avoid a name clash with the valign attribute.
• <!ENTITY% TFrame "(void|above|below|hsides|lhs|rhs|vsides|box|border)">
• The rules attribute defines which rules to draw between cells: If rules is absent then assume: "none" if border is absent or border="0" otherwise "all"
• <!ENTITY% TRules "(none | groups | rows | cols | all)">

• horizontal alignment attributes for cell contents
  char	alignment char, e.g. char=':'
  charoff	offset for alignment char

• <!ENTITY% cellhalign "align (left|center|right|justify|char) #IMPLIED char %Character; #IMPLIED charoff %Length; #IMPLIED" >
• vertical alignment attributes for cell contents
• <!ENTITY% cellvalign "valign (top|middle|bottom|baseline) #IMPLIED" >
• <!ELEMENTtable (caption?, (col*|colgroup*), thead?, tfoot?, (tbody+|tr+))>
• <!ELEMENTcaption %Inline;>
• <!ELEMENTthead (tr)+>
• <!ELEMENTtfoot (tr)+>
• <!ELEMENTtbody (tr)+>
• <!ELEMENTcolgroup (col)*>
• <!ELEMENTcol EMPTY>
• <!ELEMENTtr (th|td)+>
• <!ELEMENTth %Flow;>
• <!ELEMENTtd %Flow;>

• <!ATTLISTtable
  %attrs;
  summary	%Text;	#IMPLIED
  width	%Length;	#IMPLIED
  border	%Pixels;	#IMPLIED
  frame	%TFrame;	#IMPLIED
  rules	%TRules;	#IMPLIED
  cellspacing	%Length;	#IMPLIED
  cellpadding	%Length;	#IMPLIED
  >

• <!ATTLISTcaption %attrs; >
• colgroup groups a set of col elements. It allows you to group several semantically related columns together.

• <!ATTLISTcolgroup
  %attrs;
  span	%Number;	"1"
  width	%MultiLength;	#IMPLIED
  %cellhalign;
  %cellvalign;
  >

• col elements define the alignment properties for cells in one or more columns. The width attribute specifies the width of the columns, e.g. width=64 width in screen pixels width=0.5* relative width of 0.5 The span attribute causes the attributes of one col element to apply to more than one column.

• <!ATTLISTcol
  %attrs;
  span	%Number;	"1"
  width	%MultiLength;	#IMPLIED
  %cellhalign;
  %cellvalign;
  >

• Use thead to duplicate headers when breaking table across page boundaries, or for static headers when tbody sections are rendered in scrolling panel. Use tfoot to duplicate footers when breaking table across page boundaries, or for static footers when tbody sections are rendered in scrolling panel. Use multiple tbody sections when rules are needed between groups of table rows.
• <!ATTLISTthead %attrs; %cellhalign; %cellvalign; >
• <!ATTLISTtfoot %attrs; %cellhalign; %cellvalign; >
• <!ATTLISTtbody %attrs; %cellhalign; %cellvalign; >
• <!ATTLISTtr %attrs; %cellhalign; %cellvalign; >
• Scope is simpler than headers attribute for common tables
• <!ENTITY% Scope "(row|col|rowgroup|colgroup)">
• th is for headers, td for data and for cells acting as both

• <!ATTLISTth
  %attrs;
  abbr	%Text;	#IMPLIED
  axis	CDATA	#IMPLIED
  headers	IDREFS	#IMPLIED
  scope	%Scope;	#IMPLIED
  rowspan	%Number;	"1"
  colspan	%Number;	"1"
  %cellhalign;
  %cellvalign;
  >

• <!ATTLISTtd
  %attrs;
  abbr	%Text;	#IMPLIED
  axis	CDATA	#IMPLIED
  headers	IDREFS	#IMPLIED
  scope	%Scope;	#IMPLIED
  rowspan	%Number;	"1"
  colspan	%Number;	"1"
  %cellhalign;
  %cellvalign;
  >