<xs:element name="scheme" maxOccurs="unbounded">
    <xs:annotation>
        <xs:documentation>A scheme alias-to-URI mapping.</xs:documentation>
    </xs:annotation>
    <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
            <xs:element ref="sameAsScheme" />
            <xs:element ref="name">
                <xs:annotation>
                    <xs:documentation>A natural language name for the scheme.</xs:documentation>
                </xs:annotation>
            </xs:element>
            <xs:element ref="definition">
                <xs:annotation>
                    <xs:documentation>A natural language definition of the semantics of the scheme. This definition is normative only for the scope of the use of this scheme.</xs:documentation>
                </xs:annotation>
            </xs:element>
            <xs:element ref="note">
                <xs:annotation>
                    <xs:documentation>Additional natural language information about the scheme.</xs:documentation>
                </xs:annotation>
            </xs:element>
            <xs:element name="sameAs">
                <xs:annotation>
                    <xs:documentation>Use is DEPRECATED - use sameAsScheme instead. (A URI which identifies another scheme with concepts that use the same codes and are semantically equivalent to the concepts of this scheme)</xs:documentation>
                </xs:annotation>
                <xs:complexType>
                    <xs:simpleContent>
                        <xs:extension base="IRIType">
                            <xs:attribute name="g2flag" type="xs:string" use="optional" fixed="DEPR-SCH">
                                <xs:annotation>
                                    <xs:documentation>DO NOT USE this attribute, for G2 internal maintenance purposes only.</xs:documentation>
                                </xs:annotation>
                            </xs:attribute>
                        </xs:extension>
                    </xs:simpleContent>
                </xs:complexType>
            </xs:element>
        </xs:choice>
        <xs:attribute name="alias" type="xs:NCName" use="required">
            <xs:annotation>
                <xs:documentation>A short string used by the provider as a replacement for a scheme URI.</xs:documentation>
            </xs:annotation>
        </xs:attribute>
        <xs:attribute name="uri" type="IRIType" use="required">
            <xs:annotation>
                <xs:documentation>The URI which identifies the scheme.</xs:documentation>
            </xs:annotation>
        </xs:attribute>
        <xs:attribute name="authority" type="IRIType">
            <xs:annotation>
                <xs:documentation>Defines the authority controlling this scheme</xs:documentation>
            </xs:annotation>
        </xs:attribute>
        <xs:anyAttribute namespace="##other" processContents="lax" />
    </xs:complexType>
</xs:element>