Each content model starts with a model header, which provides an introduction
to the model containing description, author, publication date, and version number. All parts
of the model introduction are optional.
<xs:element name="model">
<xs:attributeGroup ref="name" />
...
<xs:complexType>
<xs:sequence>
<xs:element name="description" type="string"maxOccurs="1" minOccurs="0" />
<xs:element name="author" type="string"maxOccurs="1" minOccurs="0" />
<xs:element name="published" type="date"maxOccurs="1" minOccurs="0" />
<xs:element name="version" type="string"maxOccurs="1" minOccurs="0" />
...
</xs:sequence>
...
</xs:complexType>
...
<xs:attributeGroup name="name">
<xs:attribute name="name" type="string" use="required" />
</xs:attributeGroup>
</xs:element>
A content model must be uniquely named within a given content repository. To help define unique names across all content repositories, the content metamodel supports the notion of a namespace.