(a) Port-wide processing. If a C-4 Code has been approved by the port director, the C-4 Code may be used at any Line Release site at the port.

(b) Multiple port processing. In order for a C-4 Code approved at one port to be used at another port, the entry filer must submit an application to the port director of the other port. While uniform criteria shall be applied to approving similar shipments for Line Release at all ports, a port director may exercise his discretion to deny Line Release at his port even though a similar shipment may be approved at another port.