A read-only boolean indicating whether the fabric port (Fx_Port) agreed to support the Class 2 delivery service that the logged-in Nx_Port requested, meaningful only when Class 2 was actually requested. This confirms whether Class 2's acknowledged delivery mode was actually negotiated successfully during login, which matters because a device expecting Class 2 acknowledgments won't get them if this negotiation failed. If this reads false after a device explicitly requested Class 2, an admin troubleshooting missing delivery confirmations would know the fabric didn't grant that class as expected.