<?xml version="1.0" encoding="UTF-8"?>
<!ELEMENT things (entity | group | template)*>
<!ATTLIST things
          version CDATA #REQUIRED>

<!ELEMENT entity (component)*>
<!ATTLIST entity
          name CDATA #REQUIRED
          template CDATA #IMPLIED>

<!ELEMENT group (objectReference | groupReference)*>
<!ATTLIST group
          name CDATA #REQUIRED>

<!ELEMENT template (component)*>
<!ATTLIST template
          name CDATA #REQUIRED
          template CDATA #IMPLIED>

<!ELEMENT component ANY>
<!ATTLIST component
          name CDATA #REQUIRED
          type CDATA #IMPLIED>

<!ELEMENT objectReference EMPTY>
<!ATTLIST objectReference
          name CDATA #REQUIRED>

<!ELEMENT groupReference EMPTY>
<!ATTLIST groupReference
          name CDATA #REQUIRED>