This attribute specifies the unique string, set by the operator, which
identifies the call for accounting purposes. Downstream processing
uses this attribute to correlate accounting records issued at different
nodes in the network. If the value of accountingEnabled is no, this
attribute has no effect. This attribute is also visible in the FrAtm
Dlci component when accounting is enabled. When this attribute is
an empty string, the operational correlationTag attribute in the
FrAtm Dlci component receives the value of a system-generated
correlationTag.