<!-- 

  $Id: tmstrict.dtd,v 1.1 2000/10/24 08:56:58 larsga Exp $ 

  An XML DTD supported by the Ontopia Navigator. This version is very
  strict and should be used for validating purposes. Topic map
  documents should in general always be validated before they are
  imported into the topic map system.

  Notes:

    o The use of the type property is required, i.e. all instances of
    occurs, assoc, assocrl, facet and fvalue must have a type
    attribute.  

    o All topics must be explicitly declared. The use of ID, IDREF and
    IDREFS attributes checks this for you.

    o References to information resources is done via the href
    attribute on the occurs and fvalue elements. The loctype attribute
    can be used to say what kind of locator it is. The default is URI.

    Recommended public identifier:
    '+//IDN ontopia.net//DTD Topic Map Interchange Format (Strict 1.0)//EN'

-->

<!ELEMENT topicmap (topic|assoc|facet)*
>
<!ATTLIST topicmap
   addthems IDREFS #IMPLIED
   topic CDATA #IMPLIED
>

<!-- topicmap.topic: identifies topic that represents the whole topic map. 
     Reftype: topic -->

<!ELEMENT topic (topname*, occurs*)
>
<!ATTLIST topic
   id ID #REQUIRED
   identity CDATA #IMPLIED
   linktype CDATA #IMPLIED
   scope IDREFS #IMPLIED
   types IDREFS #IMPLIED
>

<!ELEMENT topname (basename+, dispname*, sortname*)
>
<!ATTLIST topname
   scope IDREFS #IMPLIED
>

<!ELEMENT basename (#PCDATA)
>
<!ATTLIST basename
   scope IDREFS #IMPLIED
>

<!ELEMENT sortname (#PCDATA)
>
<!ATTLIST sortname
   scope IDREFS #IMPLIED
>

<!ELEMENT dispname (#PCDATA)
>
<!ATTLIST dispname
   scope IDREFS #IMPLIED
>

<!ELEMENT occurs EMPTY
>
<!ATTLIST occurs
   href CDATA #REQUIRED
   loctype CDATA #IMPLIED
   occrl CDATA #IMPLIED
   scope IDREFS #IMPLIED
   type IDREF #REQUIRED
>

<!ELEMENT assoc (assocrl+)
>
<!ATTLIST assoc
   linktype CDATA #IMPLIED
   scope IDREFS #IMPLIED
   type IDREF #REQUIRED
>

<!ELEMENT assocrl EMPTY
>
<!ATTLIST assocrl
   anchrole CDATA #IMPLIED
   href IDREF #REQUIRED
   type IDREF #REQUIRED
>

<!ELEMENT facet (fvalue)+
>
<!ATTLIST facet
   linktype CDATA #IMPLIED
   type IDREF #REQUIRED
>

<!ELEMENT fvalue EMPTY
>
<!ATTLIST fvalue
   facetval CDATA #IMPLIED
   href CDATA #REQUIRED
   loctype CDATA #IMPLIED
   type IDREF #REQUIRED
>