The global Axis element is the head of a substitution group. Any element that is a member of the group may be substituted for the Axis element anywhere the Axis element may be used in an instance file.
<xs:element name="Axis" type="UserAxisBaseType" abstract="true"><xs:annotation><xs:documentation>The global Axis element is the head of a substitution group. Any element that is a member of the group may be substituted for the Axis element anywhere the Axis element may be used in an instance file.</xs:documentation></xs:annotation></xs:element>