<!ELEMENT extension (DataModelProvider? , ProviderDefinesType? , ProviderImplementsType?)>
<!ATTLIST extension
point CDATA #REQUIRED
id CDATA #IMPLIED
name CDATA #IMPLIED>
<!ELEMENT DataModelProvider EMPTY>
<!ATTLIST DataModelProvider
id CDATA #IMPLIED
class CDATA #REQUIRED>
<!ELEMENT ProviderDefinesType EMPTY>
<!ATTLIST ProviderDefinesType
providerType CDATA #REQUIRED
providerID CDATA #REQUIRED>
<!ELEMENT ProviderImplementsType EMPTY>
<!ATTLIST ProviderImplementsType
providerType CDATA #REQUIRED
providerID CDATA #REQUIRED>