A unique value used by this host system to identify this
conceptual row in the 'xcmSvcMonServiceDetailTable', OR a common
value shared across a set of related conceptual rows (with
different values of 'xcmSvcMonServiceDetailType'.
Usage: For service detail types which are single-valued, this
index SHALL be used to correlate related single-valued details.
Usage: For service detail types which are multi-valued, this
index SHALL be used to enumerate lists of multi-valued details.