Message-Level Counters

Global Custom Properties that are defined to be of type “Message-level counter” behave the same as regular “counters”, except that they are incremented only the first time they are referenced within each Message. Thus if there is more than one ISSE in the same Message referencing the same Global Custom Property of type “Message-level counter”, that property will only be incremented once for that Message and all of those ISSE substitutions within that Message will have the same value substituted.