Can be used to uniquely identify the object represented by this element for external binding reference purposes.
The value of the refID shall be unique for each object within the AVFunction and is implementation-specific. May be a GUID.
Source
<xsi:element name="avCluster" type="avClusterControlType"><xsi:annotation><xsi:documentation>Describes the structure returned by a Cluster AVControl.</xsi:documentation></xsi:annotation></xsi:element>