18. Every sealed container required for the purpose of this Regulation shall(1) be made of a hard structure;
(2) have a volume of not less than 0.2 m3;
(3) be waterproof and impervious enough to shelter the documents deposited therein from bad weather;
(4) be equipped with a padlocked door allowing the persons in charge of the application of this Regulation to have access to the documents deposited therein;
(5) bear the notice “scaling”, in the case of a sealed container referred to in section 6 or 13, or the notice “transportation”, in the case of a sealed container referred to in section 8 or 11; and
(6) be located in an accessible place.