If this variable is non-empty it defines which calling party number must be contained in an incoming call in order of this entry to match. Together with variables isdnDspRemoteSubaddress and isdnDspTypeOfRemoteSubAdd it allows call distribution based also on calling party parameters. There are no other wildcards available other than the empty string which matches any calling party number. Also no prefix or postfix is possible, either a number is specified here which needs to fully match on an incoming call or any calling party number will be accepted. Default value is the empty string, what serves as a wildcard.