This object specifies the forward signal indicating the calling subscriber's line has International Direct Dial, IDD, capability provisioned. This flag is what permits a subscriber to place international calls without operator assistance, so its absence on a line would mean international dial attempts get intercepted or routed to an operator instead of being direct-dialed. A residential line provisioned for IDD would generate this forward signal on any international call attempt, letting it proceed as a direct-dial call rather than requiring operator intervention.