Exports.

(a) Exports may be covered by marine and transportation insurance wherever the property may be without restriction as to time, provided the coverage of the issuing companies includes the hazards of transportation.

(b) An export, as a proper subject of marine or transportation insurance, shall be deemed to acquire its character as such when designated or while being prepared for export and retain that character unless diverted for domestic trade, and if so diverted, the provisions set forth in § 91.6 (relating to domestic shipments) shall apply, provided, however, that this section shall not apply to long-established methods of insuring certain commodities, for example, cotton.