This object contains the value of the index of
the zone or alias to which this member belongs to.
If the value of the corresponding instance of
zoneMemberTypeIndex is 'zone', then this object
will contain the value of the zoneIndex object of
the zone to which this member belongs to.
If the value of the corresponding instance of
zoneMemberTypeIndex is 'alias', then this object
will contain the value of the zoneAliasIndex object
of the alias to which this member belongs to.