HTML+ DTD

<!SGML  "ISO 8879:1986"
--

Document Type Definition for the HyperText Markup Language Plus for use with the World Wide Web application (HTML+ DTD). This DTD is designed for use with SGML authoring tools and it is expected that most browsers will tolerate omissions, in particular, missing <DIVn> elements and start tags following headers, which can easily be inferred from the context.

The HTML+ DTD which is structured as an HTML core plus a number of additional modules which can be included by an entity definition in a document's <!DOCTYPE> element. You can include specific features in your document using the DOCTYPE declaration at the start, e.g.

     <!DOCTYPE htmlplus [
        <!ENTITY % HTML.tables "INCLUDE">
        <!ENTITY % HTML.forms "INCLUDE">
     ]>

This spec also allows for authors to extend the DTD and to define how any new elements are rendered in terms of existing ones. This should be used with caution.

I would like to acknowledge the influence of the TEI DTDs which proved very helpful in restructuring the DTD.

Dave Raggett 11th March 1994

Changes:

Added HTML.obsolete for obsoleted HTML elements
Added SEAL attribute to A and LINK for specifying a digital signature to attest that a linked document is unchanged.
SRC attribute added to NOTE to allow authors to override the default icon chosen on the basis of the ROLE attribute.
Switched REL/REV back to CDATA to avoid trouble with duplicate name or name token error. Using an explicit list of relationship types would force us to drop REV.
Added top/bottom alignment attribute to CAPTION
REL and REV domains now defined by parameter entities
SRC attribute added to LINK to allow images to be used in document specific toolbar
Baseline attribute added to FIG and IMG to give precise control of vertical position relative to baseline.
Revised comments for <A> and <LINK> to remove references to obsoleted timing attributes and to add a list of "standard" relationship types.
CHANGED element now uses more meaningful attribute names.
STATE dropped in favor of INPUT with TYPE="hidden". Forms now support a link to a script for client-side execution of constraints.
The element definition for DIV1..DIV6 and P no longer permit the start tag to be omitted. This was regrettably forced by a restriction in the SGML standard. Browsers must be capable of inferring them when missing,in order to cope with legacy documents.
Fixed some errors in earlier version to do with start tags and definitions of parameter entities. The content model for FIG has been changed to use a P element for text to avoid an SGML parsing problem with a line break before the caption.

--
CHARSET
        BASESET "ISO 646:1983//CHARSET
                 International Reference Version (IRV)//ESC 2/5 4/0"
        DESCSET 0   9   UNUSED
                9   2   9
                11  2   UNUSED
                13  1   13
                14 18   UNUSED
                32 95   32
               127  1   UNUSED
        BASESET "ISO Registration Number 100//CHARSET
                 ECMA-94 Right Part of Latin Alphabet Nr. 1//ESC 2/13 4/1"
        DESCSET 128  32  UNUSED
                160  95  32
                255   1  UNUSED

CAPACITY        SGMLREF
                TOTALCAP        150000
                GRPCAP          150000

SCOPE   DOCUMENT
SYNTAX
        SHUNCHAR CONTROLS  0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
                           19 20 21 22 23 24 25 26 27 28 29 30 31 127 255
        BASESET "ISO 646:1983//CHARSET
                 International Reference Version (IRV)//ESC 2/5 4/0"
        DESCSET 0 128 0
        FUNCTION RE         13
                 RS         10
                 SPACE      32
                 TAB SEPCHAR 9
        NAMING   LCNMSTRT ""
                 UCNMSTRT ""
                 LCNMCHAR ".-"
                 UCNMCHAR ".-"
                 NAMECASE GENERAL YES
                          ENTITY  NO
        DELIM    GENERAL  SGMLREF
                 SHORTREF SGMLREF
        NAMES    SGMLREF
        QUANTITY SGMLREF
                 NAMELEN  32
                 TAGLVL   100
                 LITLEN   1024
                 GRPGTCNT 150
                 GRPCNT   64

FEATURES
  MINIMIZE
    DATATAG  NO
    OMITTAG  YES
    RANK     NO
    SHORTTAG NO
  LINK
    SIMPLE   NO
    IMPLICIT NO
    EXPLICIT NO
  OTHER
    CONCUR  NO
    SUBDOC  NO
    FORMAL  YES
  APPINFO NONE
>

<!DOCTYPE HTMLPLUS [

<!--

DTD for HTML+

Markup minimisation should be avoided, otherwise the default <!SGML> declaration is fine. Browsers should be forgiving of markup errors, while authoring tools should enforce compliance with the DTD.

Common Attributes:

id: This attribute allows authors to name elements such as headers and paragraphs as potential destinations for links. Note that links don't specify points, but rather extended objects.
charset: This allows authors to switch to a different char set for quotations or list etc. This is particularly useful for oriental languages which need two byte character codes, e.g. see RFC 1468 "Japanese Character Encoding for Internet Messages"

ENTITY Declarations

<!ENTITY % foo "X | Y | Z"> is a macro definition for parameters and in subsequent statements, the string "%foo;" is expanded to "X | Y | Z"

Various classes of SGML text types:

CDATA: text which doesn't include markup or entity references
RCDATA: text with entity references but no markup
PCDATA: text occurring in a context in which markup and entity references may occur.

-->

<!-- Core HTML+ DTD omits following features -->
<!ENTITY % HTML.math "IGNORE">
<!ENTITY % HTML.tables "IGNORE">
<!ENTITY % HTML.figures "IGNORE">
<!ENTITY % HTML.emph "IGNORE">
<!ENTITY % HTML.forms "IGNORE">
<!ENTITY % HTML.obsolete "IGNORE">

<!ENTITY % cextra "" -- for character-like elements -->
<!ENTITY % pextra "" -- for paragraph-like elements -->

<!--

%cextra; and %pextra are designed to allow document specific extensions to the HTML+ DTD, e.g.

      <!DOCTYPE htmlplus [
        <!ENTITY % cextra "|PROPNAME">
        <!ELEMENT PROPNAME - - CDATA>
      ]>

Use the RENDER element to specify how the browser should display new elements in terms of existing ones, e.g.

      <RENDER tag="PROPNAME" style="I">

-->

<!ENTITY % URL "CDATA" -- a URL or URN designating a hypertext node -->

<!--

Browsers should render the following types of emphasis distinctly when the obvious rendering is impractical

I = italic,

B = bold,

U = underline,

S = strikethru,

TT = teletype font,

SUP = superscript,

SUB = subscript

REV = reverse video for highlighting hit areas in the result of a query

Q = inline quote (render according to local conventions)

-->

<!ENTITY % emph1 "I|B|U|TT|CITE|EM|STRONG|KBD|VAR|DFN|CODE|SAMP">
<!ENTITY % emph2 "S|Q|PERSON|ACRONYM|ABBREV|CMD|ARG|REMOVED|ADDED|REV">
<!ENTITY % emph3 "SUP|SUB|CHANGED">

<![ %HTML.emph [ <!ENTITY % emph  "%emph1;|%emph2;|%emph3;"> ]]>
<!ENTITY % emph  "%emph1;">

<![ %HTML.emph [ <!ENTITY % misc1 "|RENDER|FOOTNOTE|MARGIN"> ]]>
<!ENTITY % misc1 "">

<![ %HTML.forms [ <!ENTITY % misc2 "|INPUT|TEXTAREA|SELECT"> ]]>
<!ENTITY % misc2 "">

<!ENTITY % misc "BR %misc1 %misc2; %cextra;">

<![ %HTML.figures [ <!ENTITY % text "#PCDATA|A|IMG|FIG|%emph;|%misc;"> ]]>
<!ENTITY % text "#PCDATA|A|IMG|%emph;|%misc;">

<![ %HTML.emph [ <!ENTITY % paras "P|PRE|LIT %pextra;"> ]]>
<!ENTITY % paras "P|PRE %pextra;">

<!ENTITY % lists "UL|OL|DL">

<![ %HTML.emph [ <!ENTITY % block1 "NOTE|QUOTE|ABSTRACT|ADDRESS|HR"> ]]>
<!ENTITY % block1 "ADDRESS|HR">

<![ %HTML.tables [ <!ENTITY % block2 "|TABLE"> ]]>
<!ENTITY % block2 "">

<![ %HTML.forms [ <!ENTITY % block3 "|FORM"> ]]>
<!ENTITY % block3 "">

<![ %HTML.math [ <!ENTITY % block4 "|MATH"> ]]>
<!ENTITY % block4 "">

<![ %HTML.obsolete [ <!ENTITY % block5 "|MENU|DIR|BLOCKQUOTE"> ]]>
<!ENTITY % block5 "">

<!ENTITY % block "%block1; %block2; %block3; %block4; %block5;">

<![ %HTML.emph [<!ENTITY % setup1 "& RENDER*"> ]]>
<!ENTITY % setup1 "">

<!ENTITY % setup "(TITLE? & ISINDEX? & BASE? & META* & LINK* %setup1;)">

<!ENTITY % main "%block;|%lists;|%paras;">

<!-- these entities are used to simplify element definitions -->

<!ENTITY % heading "H1|H2|H3|H4|H5|H6"> 
<!ENTITY % table "P|%heading;|%lists;">
<!ENTITY % math "BOX|ARRAY|ROOT|%text;">

<!--

Browsers should as a minimum support the following types of INPUT fields, in addition to TEXTAREA and SELECT:

     text, checkbox, radio, submit, and reset

password, int, float, date, url can be mapped to text fields while image, scribble and audio fields can be ignored

-->

<![ %HTML.forms [
 <!ENTITY % fields "text|password|checkbox|radio|submit|reset|int|
                        float|date|url|hidden|range|scribble|audio">
]]>



<!-- misc. from ISO Publishing entities -->
<!ENTITY ndash  SDATA "[ndash ]"--=en dash-->
<!ENTITY mdash  SDATA "[ndash ]"--=em dash-->
<!ENTITY ensp   SDATA "[ensp  ]"--=en space (1/2-em)-->
<!ENTITY emsp   SDATA "[emsp  ]"--=em space-->
<!ENTITY hellip SDATA "[hellip]"--=ellipsis (horizontal)-->
<!ENTITY vellip SDATA "[vellip]"--=ellipsis (vertical)-->

<!-- maths symbols when needed -->
<![ %HTML.math [
    <!ENTITY % ISOtech PUBLIC "ISO 8879-1986//ENTITIES General Technical//EN">
    %ISOtech;

    <!ENTITY % ISOgrk3 PUBLIC "ISO 8879-1986//ENTITIES Greek Symbols//EN">
    %ISOgrk3;

    <!ENTITY % ISOamso PUBLIC "ISO 8879-1986//ENTITIES Added Math Symbols: Ordinary//EN">
    %ISOamso;

    <!ENTITY % ISOamsr PUBLIC "ISO 8879-1986//ENTITIES Added Math Symbols: Relations//EN">
    %ISOamsr;

    <!ENTITY % ISOamsc PUBLIC "ISO 8879-1986//ENTITIES Added Math Symbols: Delimiters//EN">
    %ISOamsc;

    <!-- misc. from ISO Binary and Large operators -->

    <!ENTITY thinsp SDATA "[thinsp]"--=thin space (1/6 em)-->
    <!ENTITY coprod SDATA "[coprod]"--/coprod L: coproduct operator-->
    <!ENTITY prod   SDATA "[prod  ]"--/prod L: product operator-->
    <!ENTITY sum    SDATA "[sum   ]"--/sum L: summation operator-->
]]>

<!-- Basic types of elements:
  <!ELEMENT tagname - - CONTENT> elements needing end tags
  <!ELEMENT tagname - O CONTENT> elements with optional end tags
  <!ELEMENT tagname - O EMPTY> elements without content or end tags

The content definition is:

an entity definition as defined above
a tagname
(brackets enclosing the above)

These may be combined with the operators:

A*: A occurs zero or more times
A+: A occurs one or more times
A|B: implies either A or B
A?: A occurs zero or one times
A,B: implies first A then B
A&B: either or both A and B (in either order A B or B A)

-->

<!ELEMENT HTMLPLUS O O (HEAD, BODY)>
<!ATTLIST HTMLPLUS
        version CDATA #IMPLIED -- the HTML+ version number --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT HEAD - O (%setup;) -- delimits document wide properties -->
<!ELEMENT BODY - O ((%main;)*, DIV6*, DIV5*, DIV4*, DIV3*, DIV2*, DIV1*)>

<!--

Browsers must tolerate missing DIVn tags, e.g. the presence of an <H1> tag implies a DIV1 element enclosing it and the following text. The SGML standard unfortunately doesn't permit such inferences due to a decision made to simplify writing general SGML parsers.

-->

<!ELEMENT DIV1 - - (H1, (%main;)*, DIV6*, DIV5*, DIV4*, DIV3*, DIV2*)>
<!ELEMENT DIV2 - - (H2, (%main;)*, DIV6*, DIV5*, DIV4*, DIV3*)>
<!ELEMENT DIV3 - - (H3, (%main;)*, DIV6*, DIV5*, DIV4*)>
<!ELEMENT DIV4 - - (H4, (%main;)*, DIV6*, DIV5*)>
<!ELEMENT DIV5 - - (H5, (%main;)*, DIV6*)>
<!ELEMENT DIV6 - - (H6, (%main;)*)>

<!ATTLIST (DIV6|DIV5|DIV4|DIV3|DIV2|DIV1)
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- Document headers -->
<!ELEMENT (%heading;) - - (#PCDATA | %emph;)+>
<!ATTLIST (%heading;)
        id      ID      #IMPLIED -- defines link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- character emphasis -->
<!ELEMENT (%emph1;) - - (%text;)*>
<!ATTLIST (%emph1;)
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!--

Paragraphs which act as containers for the following text

Browsers must be capable of inferring missing start tags from the content model. Basically, if the parser comes across unexpected %text; then there's a missing .

-->
<!ELEMENT P - O (%text;)+>
<!ATTLIST P
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        align   (left|indent|center|right|justify) left>

<!ELEMENT HR - O EMPTY -- Horizontal Rule -->
<!ELEMENT BR - O EMPTY -- forced line break -->

<!ELEMENT PRE - - (%text;)+ -- preformatted fixed pitch text -->
<!ATTLIST PRE
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT ADDRESS - - (P)+ -- info on author -->
<!ATTLIST ADDRESS
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- Lists which can be nested -->
<!ELEMENT OL - - (LI)+ -- ordered list -->
<!ATTLIST OL
        id      ID      #IMPLIED
        charset CDATA   #IMPLIED    -- eg "ISO-2022-JP" for japanese --
        compact (compact) #IMPLIED  -- reduced interitem spacing -->

<!ELEMENT UL - - (LI)+ -- unordered list -->
<!ATTLIST UL
        id      ID      #IMPLIED    -- link destination --
        charset CDATA   #IMPLIED    -- eg "ISO-2022-JP" for japanese --
        compact (compact) #IMPLIED  -- reduced interitem spacing --
        plain   (plain) #IMPLIED    -- suppress bullets --
        wrap (vert|horiz|none) none -- multicolumn list wrap style -->

<!-- List items for UL and OL lists
 The icon or label overides the default rendering -->
<!ELEMENT LI - O (DL|UL|OL|P|HR)+ -- should we add PRE? -->
<!ATTLIST LI
        id      ID      #IMPLIED
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        icon    %URL;   #IMPLIED -- icon for use in place of bullet --
        label   CDATA   #IMPLIED -- when you can't show the icon -->

<!-- Definition Lists (terms + definitions) -->
<!ELEMENT DL - - (DT*,DD)+>
<!ATTLIST DL
        id      ID      #IMPLIED
        charset CDATA   #IMPLIED    -- eg "ISO-2022-JP" for japanese --
        compact (compact) #IMPLIED  -- reduced interitem spacing -->

<!ELEMENT DT - O (%text;)+          -- term text -- >
<!ELEMENT DD - O (P|UL|OL|DL|HR)+   -- definition text (should we add PRE?)-- >
<!ATTLIST (DT|DD)
        id      ID      #IMPLIED
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!--

Hypertext Links from points within document nodes

The HREF attribute specifies the link destination as a URL or URN. In figures, the SHAPE attribute defines the extent of the link as a polygonal region, and is used with the FIG element.
The PRINT attribute determines how the browser should deal with links when printing this document. This makes it possible for users to print a document and related subdocuments with a single menu action. If PRINT="Section", then the link is followed and printed as a follow-on section after the current document. If PRINT="Footnote" and the linked document is sufficiently small then it is included as a footnote. If PRINT="Reference" then the document's URL (and title) is included in a footnote or in a list of references at the end of the document.
The TITLE attribute may be used for links in which the destination node doesn't define a title itself, e.g. non-html documents.
The REL attribute is used to specify how the browser interprets the link when this document is being used as a hypertext path REL="Path" causes the linked document to be treated as a path and inserted into the current path, while REL="Node" treats the linked document as a node on the current path. REL="Embed" is a hint to embed the referenced node into the current document.
The SEAL attribute allows authors to specify a digital signature of linked documents to check that they haven't been changed.

-->

<!ELEMENT A - - (#PCDATA | IMG | %emph;)*>
<!ATTLIST A
        id      ID      #IMPLIED -- as target of link --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        shape   CDATA   #IMPLIED -- list of points for shaped buttons --
        href    %URL;  #IMPLIED -- destination node --
        rel     CDATA   #IMPLIED -- forward relationship type --
        rev     CDATA   #IMPLIED --  reverse relationship type --
        print   CDATA   #IMPLIED -- reference/footnote/section --
        title   CDATA   #IMPLIED -- when otherwise unavailable --
        seal    CDATA   #IMPLIED -- MD5 digital signature -->

<!--

Other kinds of relationships between documents

There are a set of standard RELationship types which alter the browser's navigation menu:

UseIndex: searchable index
UseGlossary: shared glossary
Contents: shared contents page
Previous: previous document in a hypertext path
Next: next document in a hypertext path
Bookmark: named with the title attribute
Made: Defines who is the "maker" of this document
Help: provides help on this document
Annotation: an additional note on current document
Reply: a note with equal footing to current document
Subdocument: defines parent->child relationship
Parent: defines child->parent relationship
StyleSheet: an associated style sheet

Bookmarks allow authors to define a set of useful links which are to be accessed via a menu, rather than as conventional in-line hypertext links. Previous and Next links are inserted by the browser when interpreting a separate document as a path. See above description of REL="Node" and REL="Path" for <A>.

The FROM attribute makes it possible to specify annotation links separately from the document text flow. The FROM attribute specifies an ID for the source of a link, while the HREF attribute specifies its destination. HTTP servers can use the WWW-Link: header to "insert" such annotations into documents.

-->

<!ELEMENT LINK - O EMPTY>
<!ATTLIST LINK
        id      ID      #IMPLIED -- to allow meta info on links --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        from    IDREF   #IMPLIED -- starting point --
        href    %URL;  #REQUIRED -- destination node --
        rel     CDATA   #IMPLIED -- forward relationship type --
        rev     CDATA   #IMPLIED -- reverse relationship type --
        src     %URL;   #IMPLIED -- an image for displaying link --
        print   CDATA   #IMPLIED -- reference/footnote/section --
        title   CDATA   #IMPLIED -- when otherwise unavailable --
        seal    CDATA   #IMPLIED -- MD5 digital signature -->

<!-- Document title -->
<!ELEMENT TITLE - - (#PCDATA | %emph;)+>
<!ATTLIST TITLE
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- Original document URL for resolving relative URLs  -->
<!ELEMENT BASE - O EMPTY>
<!ATTLIST BASE HREF %URL; #IMPLIED>

<!-- Signifies the document's URL accepts queries,
     and may be implied by HTTP header info -->
<!ELEMENT ISINDEX - O EMPTY>
<!ATTLIST ISINDEX href %URL; #IMPLIED -- defaults to document's URL -->

<!--

Servers should read the document head to generate HTTP headers corresponding to META elements, e.g. if the document contains:

        <meta name="Expires" value="Tue, 04 Dec 1993 21:29:02 GMT">

The server should include the HTTP date format header field:

        Expires: Tue, 04 Dec 1993 21:29:02 GMT

Other likely names are "Created", "Owner" (a name) and "Reply-To" (an email address)

-->

<!ELEMENT META - O EMPTY>
<!ATTLIST META
        id      ID      #IMPLIED -- to allow meta info  --
        name    CDATA   #IMPLIED -- HTTP header e.g. "Expires" --
        value   CDATA   #IMPLIED -- associated value -->

<![ %HTML.obsolete [

<!ELEMENT (MENU|DIR) - - (LI)+ -- plain single/multicolumn lists-->
<!ATTLIST (MENU|DIR)
        compact (compact) #IMPLIED  -- reduced interitem spacing -->

<!ELEMENT BLOCKQUOTE - - (P)+ -- extended quotes -->

]]>

<![ %HTML.emph [

<!-- additional character emphasis -->
<!ELEMENT (%emph2;) - - (%text;)*>
<!ATTLIST (%emph2;)
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT (SUP|SUB) - - (%text;)* -- superscripts and subscripts -->
<!ATTLIST (SUP|SUB)
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT (FOOTNOTE|MARGIN) - - (%text;)* -(FOOTNOTE|MARGIN)>
<!ATTLIST (FOOTNOTE|MARGIN)
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- RENDER only appears in the document head -->
<!ELEMENT RENDER -O EMPTY -- how to render unknown elements -->
<!ATTLIST RENDER
        id      ID      #IMPLIED -- to allow meta info  --
        tag     CDATA   #IMPLIED -- tag name --
        equiv   CDATA   #IMPLIED -- HTML+ equivalent tag name --
        style   NAMES   #IMPLIED -- space separated list of styles -->

<!ELEMENT LIT - - (TAB|%text;)+ -- literal variable pitch text -->
<!ATTLIST LIT
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT TAB - O EMPTY -- tabs for imported text -->
<!ATTLIST TAB
        id      ID      #IMPLIED -- to allow meta info  --
        at      NUMBER  #IMPLIED -- in em units or width of an "m" --
        align   (left|center|right|decimal) left -- tab alignment -->

<!ELEMENT QUOTE - - (P*) -- block quote -->
<!ATTLIST QUOTE
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT ABSTRACT - - (P*) -- document summary -->
<!ATTLIST ABSTRACT
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- often rendered with an icon in left margin,
     the role is shown before the first paragraph -->
<!ELEMENT NOTE - - (P*) -- admonishment -->
<!ATTLIST NOTE
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        src     %URL;   #IMPLIED -- url for the icon --
        role (Simple|Tip|Note|Warning|Error) Simple >

<!-- change bars can bridge markup boundaries -->
<!ELEMENT CHANGED - O EMPTY>
<!ATTLIST CHANGED -- one of id or idref is always required --
        begin    ID      #IMPLIED -- signals beginning of changes --
        end      IDREF   #IMPLIED -- signals end of changes -->
]]>


<![ %HTML.figures [ <!ENTITY % HTML.captions "INCLUDE"> ]]>
<![ %HTML.tables [ <!ENTITY % HTML.captions "INCLUDE"> ]]>
<!ENTITY % HTML.captions "IGNORE">

<![ %HTML.captions [

<!ELEMENT CAPTION - - (%text;)+ -- table or figure caption -->
<!ATTLIST CAPTION
        id      ID      #IMPLIED
        align (top|bottom) #IMPLIED
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->
]]>

<![ %HTML.tables [

<!-- a pre-pass is needed to count columns and determine
     min/max widths before sizing to match window size -->

<!ELEMENT TABLE - - (CAPTION?, TR*) -- mixed headers and data -->
<!ATTLIST TABLE
        id      ID      #IMPLIED
        border (border) #IMPLIED -- draw borders --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- browsers should tolerate an omission of the first
  <TR> tag as it is implied by the context -->
<!ELEMENT TR - O (TH|TD)* -- acts like row separator -->
<!ATTLIST TR id ID #IMPLIED>

<!ELEMENT TH - O (%table;)* -- a header cell -->
<!ATTLIST TH
        id      ID      #IMPLIED
        colspan NUMBER    1      -- columns spanned --
        rowspan NUMBER    1      -- rows spanned --
        align (left|center|right|numeric) center
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT TD - O (%table;)* -- a data cell -->
<!ATTLIST TD
        id      ID      #IMPLIED
        colspan NUMBER    1      -- columns spanned --
        rowspan NUMBER    1      -- rows spanned --
        align (left|center|right|numeric) center
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->
]]>

<![ %HTML.forms [

<!--

The form contents are sent to the server upon pressing a submit button. Forms can be associated with scripts, e.g. to make one selection field effect which options are enabled for other fields.

Clicking on a selection or typing into a text field result in events which are processed by the script. Event handlers are associated with each field or with the form itself. The script language is deliberately restricted to avoid any security issues.

Fields can be disabled (greyed out) or marked as being in error. The MESSAGE element may be used by the server to set error messages. Servers can store state information in forms with hidden input fields. These are not displayed and can be used to hold transaction handles etc.

-->

<!ELEMENT FORM - - ((%main;)*, MESSAGE?) -(FORM) -- forms can't be nested -->
<!ATTLIST FORM
        id      ID      #IMPLIED
        action  %URL;   #IMPLIED -- defaults for URL for current doc --
        method  CDATA   #IMPLIED -- GET, PUT, POST, DELETE etc. --
        enctype CDATA   #IMPLIED -- encoding type for form transfers --
        script  %URL;   #IMPLIED -- locally executed event handlers --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!--

Types of INPUT field:

text: one line text fields, size gives visible width of field in chars where value may grow beyond this up to MAX (MAXLENGTH) chars.
password: like text fields but with no echo of typed characters
checkbox: for simple yes/no choices
radio: for one from many choices, each radio button in a group has the same NAME but a different VALUE.
submit: Sends form to server. If the SRC attribute specifies an icon the point clicked is sent to the server. The default NAME for this field is "Submit". Use different names for multiple submit buttons in a form.
reset: Resets fields to their initial values.
int: for input of integers, SIZE attribute gives width of field
float: for input of floating point numbers
date: for input of dates
url: for input of universal resource locators
hidden: used by server for state info, opaque to client
range: integer range from MIN to MAX, rendered as a slider etc.
scribble: pen input, which may include time and pressure info
audio: sound input with up to MAX seconds

-->
<!ELEMENT INPUT - O EMPTY>
<!ATTLIST INPUT
        id      ID      #IMPLIED -- to allow meta info  --
        name    CDATA   #IMPLIED -- attribute name (may not be unique) --
        type    (%fields) text   -- a wide variety of field types --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        size    CDATA   #IMPLIED -- visible size of text fields --
        min     NUMBER  #IMPLIED -- for range controls --
        max     NUMBER  #IMPLIED -- for range controls or text fields --
        maxlength NUMBER #IMPLIED -- max length of text fields (equiv to max)--
        value   CDATA   #IMPLIED -- attribute value (altered by user) --
        checked (checked) #IMPLIED -- for check boxes and radio buttons --
        disabled (disabled) #IMPLIED -- if grayed out --
        error   (error) #IMPLIED -- if in error --
        src      %URL;  #IMPLIED -- for SUBMIT, SCRIBBLE & AUDIO fields --
        alt     CDATA   #IMPLIED -- alternative text for VT100's etc --
        align (top|middle|bottom) top -- for IMAGE fields only -->

<!-- multiline text input fields, we probably will want
     to generalise this to accept arbitrary clipboard data
     e.g. hypertext and images, in addition to plain text -->
<!ELEMENT TEXTAREA - - RCDATA -- multi-line text fields -->
<!ATTLIST TEXTAREA
        id      ID      #IMPLIED -- to allow meta info  --
        name    CDATA   #IMPLIED -- attribute name (may not be unique) --
        cols    NUMBER  #IMPLIED -- visible width in characters --
        rows    NUMBER  #IMPLIED -- visible height in characters --
        wrap    (wrap)  #IMPLIED -- wrap input in text area --
        disabled (disabled) #IMPLIED -- if grayed out --
        error   (error) #IMPLIED -- if in error --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- the EDIT attribute when present allows you to type and
     edit the selected option -->
<!ELEMENT SELECT - - (OPTION+) -- combo style selection lists -->
<!ATTLIST SELECT
        id      ID      #IMPLIED -- to allow meta info  --
        name    CDATA   #IMPLIED -- attribute name (may not be unique) --
        edit    NUMBER  #IMPLIED -- width of editable selection --
        multiple (multiple) #IMPLIED -- permits multiple selections --
        error   (error) #IMPLIED -- if in error --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!ELEMENT OPTION - O RCDATA>
<!ATTLIST OPTION
        id      ID      #IMPLIED -- to allow meta info  --
        value   CDATA   #IMPLIED -- attribute value --
        selected (selected) #IMPLIED -- if initially selected --
        disabled (disabled) #IMPLIED -- if grayed out --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!--

Scripts executed by the client need a way of displaying warning/error messages. We define an element so that the server too can initialise this one-per-form message area. Clients should preferably avoid displaying the message in-line, as the window size may prevent the user from seeing the message.

 -->
<!ELEMENT MESSAGE - O RCDATA -- place for error/warning/info -->
<!ATTLIST MESSAGE
        id      ID      #IMPLIED -- to allow meta info  --
        status  (info|warning|error) info
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->
]]>

<![ %HTML.figures [

<!--

Figures which subsume the role of the earlier IMG element.

Behaves identically to IMG for align = top, middle or bottom. Otherwise figure is inserted after next line break (soft or hard). For align=left, the image is left aligned and text is flowed on the right of the image, and similarly for align=right, with no text flow for align=center (the default). The caption is placed under the image.

Finer control of the vertical positioning relative to the text line is possible with the baseline attribute. When present, the figure acts like the IMG element but is shifted so that the baseline occurs at the specified number of pixels above the bottom of the image. If this is given as a floating point number, it is interpreted as a fraction of the image height and must lie in the range (0.0 to 1.0)

The <A> element is used for shaped buttons handled by browser, while the ISMAP mechanism sends pointer clicks/drags to server. The text contained by this element is used for text-only displays and authors should remember to provide effective descriptions, including label text for shaped buttons.

-->
<!ELEMENT FIG - - (CAPTION?, P*)>
<!ATTLIST FIG
        id      ID      #IMPLIED
        align   (top|middle|bottom|left|center|right) center -- position --
        baseline NUMBER #IMPLIED -- height of baseline above image bottom --
        ismap   (ismap) #IMPLIED -- server can handle mouse clicks/drags --
        src     %URL;   #IMPLIED -- link to image data --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->
]]>

<!NOTATION GIF PUBLIC "-//local//NOTATION GIF Image//EN">
<!NOTATION XBM PUBLIC "-//local//NOTATION XBM Image//EN">
<!-- img is left in for at least the short term -->
<!ELEMENT IMG - O EMPTY>
<!ATTLIST IMG
        src     %URL;   #REQUIRED -- where to get image data --
        align   (top|middle|bottom) top  -- top, middle or bottom --
        baseline NUMBER #IMPLIED -- height of baseline above image bottom --
        alt     CDATA   #IMPLIED -- description for text-only displays --
	type	NOTATION(GIF|XBM) #IMPLIED
        ismap   (ismap) #IMPLIED  -- send mouse clicks/drags to server -->

<![ %HTML.math [

<!--

Proposal for representing formulae

Delimiters should stretch to match the size of the delimited object.  and  are used for subscripts and superscripts

                                          i j
      X <SUP>i</SUP>Y<SUP>j</SUP>  is   X  Y

i.e. the space following the X disambiguates the binding.

-->

<!ELEMENT MATH - - (%math;)*>
<!ATTLIST MATH id ID #IMPLIED>

<!-- Invisible brackets which may also be
     used for numerators and denominators:

                                   1 + X
     <BOX>1 + X<OVER>Y</BOX>  is  _______
                                     Y

                                 _____
     <BOX><OVER>X + Y</BOX>  is  X + Y
-->
<!ELEMENT BOX - - ((%math;)*, (OVER, (%math;)*)?)>

<!--

Horizontal line between numerator and denominator

The symbol attribute allows authors to supply an entity name for an arrow symbol etc.

 -->
<!ELEMENT OVER - O EMPTY>
<!ATTLIST OVER symbol ENTITY #IMPLIED>

<!-- Roots - default to square root -->
<!ELEMENT ROOT - - (%math;)*>
<!ATTLIST ROOT root CDATA #IMPLIED>

<!--

LaTeX like arrays.

The align attribute specifies a single letter for each column, which also determines how the column should be aligned, e.g. align=ccc"

        "l"     left
        "c"     center
        "r"     right
-->
<!ELEMENT ARRAY - - (ITEM)+>
<!ATTLIST ARRAY align CDATA #REQUIRED>

<!ELEMENT ITEM - O (%math;)*>

]]>

<!-- The END -->
]>