Every cask before being packed or repacked for exportation shall first be searched, examined, and approved by a packer; and shall, when packed or repacked for exportation, be branded legibly on one head with the kind of fish it contains and the weight of the fish or the capacity of the cask with the first letter of the first name and the whole of the surname of the packer, the name of the town, and the words Rhode Island, in letters not less than three-fourths of an inch (¾”) long, to denote that the cask is merchantable and in good order for exportation.