Domestic shipments.

(a) Domestic shipments on consignment for sale or distribution, exhibit, trial, or approval or auction—while in transit in the custody of others, and while being returned—may be covered by marine and transportation insurance provided that in no event shall the policy cover shipments on premises owned, leased, or operated by the consignor.

(b) Domestic shipments not on consignment may be covered by marine or transportation insurance provided that the coverage of the issuing companies includes the hazards of transportation beginning and ending within the United States and that such shipments shall not be covered at manufacturing premises nor after arrival at premises owned, leased, or operated by assured or purchaser.