<xs:element name="groupSet" minOccurs="0">
    <xs:annotation>
        <xs:documentation>A hierarchical set of groups</xs:documentation>
    </xs:annotation>
    <xs:complexType>
        <xs:sequence>
            <xs:element name="group" maxOccurs="unbounded">
                <xs:annotation>
                    <xs:documentation>A mixed set of group references and links</xs:documentation>
                </xs:annotation>
                <xs:complexType>
                    <xs:choice minOccurs="0" maxOccurs="unbounded">
                        <xs:element name="groupRef">
                            <xs:annotation>
                                <xs:documentation>A reference to a group local to the package</xs:documentation>
                            </xs:annotation>
                            <xs:complexType>
                                <xs:attribute name="idref" type="xs:IDREF" use="required">
                                    <xs:annotation>
                                        <xs:documentation>The reference to the id of a local group</xs:documentation>
                                    </xs:annotation>
                                </xs:attribute>
                                <xs:anyAttribute namespace="##other" processContents="lax" />
                            </xs:complexType>
                        </xs:element>
                        <xs:element name="itemRef" type="Link1Type">
                            <xs:annotation>
                                <xs:documentation>A reference to a target item or Web resource</xs:documentation>
                            </xs:annotation>
                        </xs:element>
                    </xs:choice>
                    <xs:attribute name="id" type="xs:ID" use="required">
                        <xs:annotation>
                            <xs:documentation>The local identifier of the group</xs:documentation>
                        </xs:annotation>
                    </xs:attribute>
                    <xs:attribute name="creator" type="QCodeType">
                        <xs:annotation>
                            <xs:documentation>If the supporting property has no value, specifies which party (person, organisation or system) will edit the property. If the supporting property has a value, specifies which party (person, organisation or system) has edited the property</xs:documentation>
                        </xs:annotation>
                    </xs:attribute>
                    <xs:attribute name="modified" type="DateOptTimeType">
                        <xs:annotation>
                            <xs:documentation>The date (and, optionally, the time) when the property was last modified. The initial value is the date (and, optionally, the time) of creation of the property</xs:documentation>
                        </xs:annotation>
                    </xs:attribute>
                    <xs:attribute name="role" type="QCodeType" use="required">
                        <xs:annotation>
                            <xs:documentation>The part this group plays within its container</xs:documentation>
                        </xs:annotation>
                    </xs:attribute>
                    <xs:attribute name="mode" type="QCodeType">
                        <xs:annotation>
                            <xs:documentation>An indication whether the elements in the group are complementary and unordered, complementary and ordered or a set of alternative elements</xs:documentation>
                        </xs:annotation>
                    </xs:attribute>
                    <xs:attributeGroup ref="i18nAttributes" />
                    <xs:anyAttribute namespace="##other" processContents="lax" />
                </xs:complexType>
            </xs:element>
        </xs:sequence>
        <xs:attribute name="root" type="xs:IDREF" use="required">
            <xs:annotation>
                <xs:documentation>The reference to a local group acting as the root of the hierarchy of groups</xs:documentation>
            </xs:annotation>
        </xs:attribute>
        <xs:anyAttribute namespace="##other" processContents="lax" />
    </xs:complexType>
</xs:element>