<xs:element name="scheme" maxOccurs="unbounded">
    <xs:annotation>
        <xs:documentation>A scheme alias-to-URI mapping.</xs:documentation>
    </xs:annotation>
    <xs:complexType>
        <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:attributeGroup ref="editAttributes" />
        <xs:anyAttribute namespace="##other" processContents="lax" />
    </xs:complexType>
</xs:element>