
<!-- Author: Rob Sanderson (azaroth@liv.ac.uk)  -->
<!-- Version: 2.0                               -->
<!-- Date: 16 February, 2004                      -->
<!-- Documentation:  http://explain.z3950.org/  -->

<!ELEMENT explain (serverInfo, databaseInfo?, metaInfo?, indexInfo?, (recordInfo|schemaInfo)?, configInfo?)>
<!ATTLIST explain xmlns CDATA #FIXED "http://explain.z3950.org/dtd/2.0/"
                  authoritative (true|false) "false"
                  id CDATA #IMPLIED>

<!-- Server Info -->

<!ELEMENT serverInfo (host, port, database, authentication?)>
<!ATTLIST serverInfo
                     protocol CDATA "Z39.50"
		     version CDATA "3"
                     transport CDATA "http"
		     wsdl CDATA #IMPLIED>

<!ELEMENT host (#PCDATA)>
<!ELEMENT port (#PCDATA)>
<!ELEMENT database (#PCDATA)>
<!ATTLIST database
                   numRecs CDATA #IMPLIED
                   lastUpdate CDATA #IMPLIED>

<!ELEMENT authentication (open | (user?, group?, password?))>
<!ATTLIST authentication
                         required (true|false) "true">
<!ELEMENT open (#PCDATA)>
<!ELEMENT user (#PCDATA)>
<!ELEMENT group (#PCDATA)>
<!ELEMENT password (#PCDATA)>

<!-- Database Info -->

<!ELEMENT databaseInfo (title*, description*, (author | contact | extent | history | langUsage | restrictions | subjects | links | implementation)*  )>


<!-- Note that title is used in more than just databaseInfo -->
<!ELEMENT title (#PCDATA)>
<!ATTLIST title
                primary (true|false) #IMPLIED
                lang CDATA #IMPLIED>

<!ELEMENT description (#PCDATA)>
<!ATTLIST description
                      primary (true|false) #IMPLIED
                      lang CDATA #IMPLIED>

<!ELEMENT author (#PCDATA)>
<!ATTLIST author
                 primary (true|false) #IMPLIED
                 lang CDATA #IMPLIED>

<!ELEMENT contact (#PCDATA)>
<!ATTLIST contact
                  primary (true|false) #IMPLIED
                  lang CDATA #IMPLIED>

<!ELEMENT extent (#PCDATA)>
<!ATTLIST extent
                 primary (true|false) #IMPLIED
                 lang CDATA #IMPLIED>


<!ELEMENT history (#PCDATA)>
<!ATTLIST history
                  primary (true|false) #IMPLIED
                  lang CDATA #IMPLIED>

<!ELEMENT langUsage (#PCDATA)>
<!ATTLIST langUsage
                    codes CDATA #IMPLIED
                    primary (true|false) #IMPLIED
                    lang CDATA #IMPLIED>

<!ELEMENT restrictions (#PCDATA)>
<!ATTLIST restrictions
                       primary (true|false) #IMPLIED
                       lang CDATA #IMPLIED>

<!ELEMENT subjects (subject+)>
<!ELEMENT subject (#PCDATA)>

<!ELEMENT links (link+)>
<!ELEMENT link (#PCDATA)>
<!ATTLIST link
               type CDATA #IMPLIED>

<!ELEMENT implementation (title*)>
<!ATTLIST implementation
               identifier CDATA #IMPLIED
               version CDATA #IMPLIED>


<!-- Meta Info -->

<!ELEMENT metaInfo (dateModified, (aggregatedFrom, dateAggregated)?)>

<!ELEMENT dateModified (#PCDATA)>
<!ELEMENT aggregatedFrom (#PCDATA)>
<!ELEMENT dateAggregated (#PCDATA)>

<!-- Index Info -->

<!ELEMENT indexInfo ((set | index | sortKeyword)+)>

<!ELEMENT set (title*)>
<!ATTLIST set
 	           name CDATA #REQUIRED
 	           identifier CDATA #REQUIRED>

<!ELEMENT index (title*, map+, configInfo?)>
<!ATTLIST index
                id CDATA #IMPLIED 
                search (true|false) #IMPLIED
                scan (true|false) #IMPLIED
                sort (true|false) #IMPLIED>

<!ELEMENT sortKeyword (#PCDATA)>

<!ELEMENT map ((attr+)|name)>
<!ATTLIST map
              primary (true|false) "false">

<!ELEMENT name (#PCDATA)>
<!ATTLIST name 
               set CDATA #IMPLIED>

<!ELEMENT attr (#PCDATA)>
<!ATTLIST attr
               type CDATA #REQUIRED
               set CDATA "1.2.840.10003.3.1">


<!-- Record Info and Schema Info -->

<!ELEMENT recordInfo (recordSyntax+)>
<!ELEMENT recordSyntax (elementSet+)>
<!ATTLIST recordSyntax
                       name CDATA #IMPLIED 
                       identifier CDATA #IMPLIED>
<!ELEMENT elementSet (title*)>
<!ATTLIST elementSet
                              name CDATA #REQUIRED>

<!ELEMENT schemaInfo (schema+)>
<!ELEMENT schema (title*)>
<!ATTLIST schema
                 identifier CDATA #REQUIRED
                 name CDATA #REQUIRED
                 location CDATA #IMPLIED
                 sort (true|false) "false"
                 retrieve (true|false) "true">

<!-- Config Info -->		 

<!ELEMENT configInfo ((default|setting|supports)*)>
<!ELEMENT default (#PCDATA)>
<!ATTLIST default
                  type CDATA #REQUIRED>
<!ELEMENT setting (#PCDATA)>
<!ATTLIST setting
                  type CDATA #REQUIRED>
<!ELEMENT supports (#PCDATA)>
<!ATTLIST supports 
                   type CDATA #REQUIRED>