<!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 <P> 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 <dsr@hplb.hpl.hp.com> 5th April 1994

     Changes:

     Added align attribute to headers with same values
     and meaning as for paragraphs.

     Added prologue and epilogue elements and fixed bug
     in definition of %paras with HTML.emph.

     Added entity names for standard icons c/o Bert Bos.
     This are enabled with the HTML.icons switch.

     Added PRE to content model for LI and DD, and changed
     DL to require at least one DT per DD. Math is now
     part of %text; but can't be nested.

     Tried to permit an optional epilogue following last
     division, but sgmls gave: Content model is ambiguous

     Added support for graphical menus to SELECT/OPTION.

     Liberalised content model for headers to %text;
     Added optional NOFOLD attribute to P element to
     inhibit SGML folding of whitespace.

     Dropped the LIT element and changed the TAB element
     over to the LaTeX model. Added NOWRAP to P element.
     Replaced TH/TD's align=numeric with ALIGNON="." etc.

     Made anchor NAME attribute conditional on HTML.obsolete
     Added HTML.obsolete for obsoleted HTML elements

     Added SIG 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 "INCLUDE">		<!-- INCLUDE by k16 -->
<!ENTITY % HTML.figures "INCLUDE">		<!-- INCLUDE by k16 -->
<!ENTITY % HTML.emph "INCLUDE">			<!-- INCLUDE by k16 -->
<!ENTITY % HTML.forms "INCLUDE">		<!-- INCLUDE by k16 -->
<!ENTITY % HTML.obsolete "IGNORE">
<!ENTITY % HTML.icons "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|TAB|HIDE">

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

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

<!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.obsolete [ <!ENTITY % block4 "|MENU|DIR|BLOCKQUOTE"> ]]>
<!ENTITY % block4 "">

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

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

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

<!ENTITY % main "%block;|%lists;|%paras;">
<!ENTITY % divisions "DIV6*, DIV5*, DIV4*, DIV3*, DIV2*, DIV1*">

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

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

<![ %HTML.obsolete [<!ENTITY % anchorname "name NMTOKEN #IMPLIED"> ]]>
<!ENTITY % anchorname "">

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


<!-- Core DTD includes basic Latin-1 entities -->
<!ENTITY % ISOlat1 PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN">
%ISOlat1;

<!-- additional entities normally found in Latin-1 char sets-->
<!ENTITY % ISOnum PUBLIC "ISO 8879-1986//ENTITIES Numeric and Special Graphic//EN">
%ISOnum;

<!-- diacritical marks normally found in Latin-1 char sets-->
<!ENTITY % ISOdia PUBLIC "ISO 8879-1986//ENTITIES Diacritical Marks//EN">
%ISOdia;

<!-- misc. from ISO Publishing entities -->
<!ENTITY ndash  SDATA "[ndash ]"--=en dash-->
<!ENTITY mdash  SDATA "[mdash ]"--=em dash-->	<!-- change [ndash ] to [mdash ] by k16 -->
<!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)-->

<!-- standard ISO/WWW icons courtesy of Bert Bos and Kevin Hughes, see
         gopher://gopher.let.rug.nl/00/ftp/pub/Bert/WWWicn.940218

    These can be used in place of default symbols for list items or as
    part of hypertext links, and save time needed to download images.
    Browsers can define them in terms of library images or as URL/URNs.
-->

<![ %HTML.icons [
  <!ENTITY ftp SDATA "ftp" -- ftp server -->
  <!ENTITY gopher SDATA "gopher" -- gopher server -->
  <!ENTITY telnet SDATA "telnet" -- telnet connection -->
  <!ENTITY archive SDATA "archive" -- archive server -->
  <!ENTITY filing.cabinet SDATA "filing.cabinet" -- filing cabinet -->
  <!ENTITY folder SDATA "folder" -- folder or directory -->
  <!ENTITY fixed.disk SDATA "fixed.disk" -- fixed media drive -->
  <!ENTITY disk.drive SDATA "disk.drive" -- removeable media drive -->
  <!ENTITY document SDATA "document" -- unspecified document type -->
  <!ENTITY unknown.document SDATA "unknown.document" -- unrecognised document type -->
  <!ENTITY text.document SDATA "text.document" -- text/plain, text.html etc. -->
  <!ENTITY binary.document SDATA "binary.document" -- binary data -->
  <!ENTITY binhex.document SDATA "binhex.document" -- binhex format -->
  <!ENTITY audio SDATA "audio" -- audio sequence -->
  <!ENTITY film SDATA "film" -- film or animation, such as an MPEG movie -->
  <!ENTITY image SDATA "image" -- photograph, drawing or graphic of any kind -->
  <!ENTITY map SDATA "map" -- geographical or a schematic map -->
  <!ENTITY form SDATA "form" -- fill-out form -->
  <!ENTITY mail SDATA "mail" -- email messages -->
  <!ENTITY parent SDATA "parent" -- parent of current document -->
  <!ENTITY next SDATA "next" -- next document in current sequence -->
  <!ENTITY previous SDATA "previous" -- previous document in current sequence -->
  <!ENTITY home SDATA "home" -- home document -->
  <!ENTITY toc SDATA "toc" -- table of contents -->
  <!ENTITY glossary SDATA "glossary" -- glossary of terms etc. -->
  <!ENTITY index SDATA "index" -- searchable index -->
  <!ENTITY summary SDATA "summary" -- summary -->

  <!ENTITY calculator SDATA "calculator" -- A calculator -->
  <!ENTITY caution SDATA "caution" -- Warnign sign -->
  <!ENTITY clock SDATA "clock" -- A clock -->
  <!ENTITY compressed.document SDATA "compressed.document">
  <!ENTITY diskette SDATA "diskette" -- A diskette -->
  <!ENTITY display SDATA "display" -- A computer screen -->
  <!ENTITY fax SDATA "fax" -- A fax machine -->
  <!ENTITY mail.in SDATA "mail.in" -- mail-in tray -->
  <!ENTITY mail.out SDATA "mail.out" -- mail-out tray -->
  <!ENTITY mouse SDATA "mouse" -- mouse/pointing device -->
  <!ENTITY printer SDATA "printer" -- hardcopy device -->
  <!ENTITY tn3270 SDATA "tn3270" --tn3270 terminal session -->
  <!ENTITY trash SDATA "trash" -- waste paper basket -->
  <!ENTITY uuencoded.document SDATA "uuencoded.document" -- uuencoded data -->
]]>

<!-- 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 (PROLOGUE?, %divisions;, EPILOGUE?)>

<!ELEMENT PROLOGUE O O (%main;)+>
<!ELEMENT EPILOGUE O O (%main;)+>

<!--
  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.

  It would be nice to allow an optional prologue and epilogue, before
  and after the divisions respectively. Unfortunately, the epilogue
  would lead to an ambiguous content model (according to sgmls).
-->

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

<!-- 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 <P>
 start tags from the content model. Basically, if the parser
 comes across unexpected %text; then there's a missing <P>.
-->
<!ELEMENT P - O (%text;)+>
<!ATTLIST P
        id      ID      #IMPLIED -- link destination --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        nowrap (nowrap) #IMPLIED -- don't wrap words --
        nofold (nofold) #IMPLIED -- don't fold whitespace --
        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
        start   NUMBER  1           -- sequence number for first item --
        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

 By default UL list items have bullets while OL list items
 are numbered in a style dependent on nesting. For extra impact
 specify an explicit image with the icon attribute or a string
 with the label attribute. This attribute can also be used with
 SGML entities to specify standard icons, e.g. label="&folder;"
-->

<!ELEMENT LI - O (DL|UL|OL|P|HR|PRE)+>
<!ATTLIST LI
        id      ID      #IMPLIED
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese --
        number  NUMBER  #IMPLIED -- sets sequence number for OL lists --
        icon     %URL;  #IMPLIED -- image for use in place of bullet --
        label   CDATA   #IMPLIED -- when you can't show the icon image -->

<!-- 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 (DL|UL|OL|P|HR|PRE)+   -- definition text -- >
<!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 SIG attribute allows authors to specify a digital signature
 of linked documents to check that they haven't been changed.
 It starts with a prefix denoting the algorithm used, in particular
 SIG="md5:2l3k4j2lkj423l" denotes the MD5 signature: 2l3k4j2lkj423l
 which is encoded using the standard MIME base64 representation
-->

<!ELEMENT A - - (#PCDATA | IMG | %emph;)*>
<!ATTLIST A
        id      ID      #IMPLIED -- as target of link --
        %anchorname;             -- see HTML.obsolete --
        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 --
        sig     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 "Summary", "Keywords", "Created",
 "Owner" (a name) and "Reply-To" (an email address)

 These elements can be used to construct IAFA style templates
 which describe the contents of the server. The templates are
 then used for automatic indexing of servers.

 The effectiveness of indexing is dependent on using well defined
 keywords drawn from standard sets.

 The Document-Icon header is used to specify a URL for
 use as an icon in the hotlist and history list.
-->

<!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 -->

<!-- Based on LaTeX's tabbing environment -->
<!ELEMENT TAB - O EMPTY>
<!ATTLIST TAB
        id      ID      #IMPLIED  -- used to set a tab stop --
        to      IDREF   #IMPLIED  -- move to previously defined tab stop --
        before  NUMBER  0         -- scaled em spaces before tab stop --
        after   NUMBER  0         -- scaled em spaces after tab stop -->

<!-- content is hidden, equivalent of LaTeX's \kill -->
<!ELEMENT HIDE - - (%text;) -(HIDE)>

<!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) center
        alignon CDATA   #IMPLIED -- align on decimal point etc --
        nowrap (nowrap) #IMPLIED -- don't wrap words --
        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) center
        alignon CDATA   #IMPLIED -- align on decimal point etc --
        nowrap (nowrap) #IMPLIED -- don't wrap words --
        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 to 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 as per ISMAP.
       The default NAME for this field is "Submit". The VALUE is used
       as the buttobn label. The NAME/VALUE are submitted with the form
       contents to allow servers to work out which button was pressed.
 reset: Resets fields to their initial values. The VALUE is used as the
       button label. The SRC attribute can be used for an icon button.
 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, the
        background can be initialised to an image with the SRC attribute
 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.

     The SRC attribute allows for graphical menus, e.g. users
     wanting to buy a house could click on each of the areas on
     a map that they were interested in.
 -->
<!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 --
        src      %URL;  #IMPLIED -- for graphical menus --
        charset CDATA   #IMPLIED -- eg "ISO-2022-JP" for japanese -->

<!-- The SHAPE attribute defines a region in the image that
     is specified by the SRC attribute for the SELECT element -->
<!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 --
        shape   CDATA   #IMPLIED -- list of points for shaped region --
        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 -->
]]>

<!-- 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 --
        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. <SUB> and <SUP> 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 - - (%formulae;)* -(MATH) -- math can't be nested -->
<!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 - - ((%formulae;)*, (OVER, (%formulae;)*)?)>

<!-- 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 - - (%formulae;)*>
<!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 (%formulae;)*>

]]>

<!-- The END -->
]>
