3326 INTERNATIONAL AGREEMENTS OTHER THAN TREATIES [62 STAT. address bears the words Abonnements-poste (Subscription by mail) which are sent under the Agreement concerning subscriptions to newspapers and periodicals. ARTICLE 51. Prepayment of correspondence on board ships. Correspondence mailed on the high seas, in the box on board a vessel, or handed to postal agents on board or to the commanders of vessels, may be prepaid, barring contrary agreement between the Administrations concerned, by means of the postage stamps and according to the postage rates of the country to which the said vessel belongs or by which it is maintained. If the mailing on board takes place during the stay at one of the two terminal points of the voyage or at one of the intermediate ports of call, the prepayment is valid only if it is effected by means of the postage stamps and according to the postage rates of the country in whose waters the vessel happens to be. ARTICLE 52. Franking privilege. 1. Correspondence relating to the postal service exchanged between Postal Administrations, between those Administrations and the Inter- national Bureau, between post offices of countries of the Union, and between those offices and the Administrations, as well as that for which the franking privilege is expressly provided by the provisions of the Convention, the Agreements and their Regulations, is exempt from all postal charges. 2. Except when they bear C. O . D . charges, mail articles addressed to prisoners of war or mailed by them are likewise exempt from all postal charges, not only in the countries of origin and destination but also in the intermediary countries. 3. The same is true of correspondence concerning prisoners of war, sent or received either directly or as intermediary by the Central Information Office for Prisoners of War, as provided for in Article 79 of the International Convention of Geneva of July 27, 1929, or by information offices which may be established for the benefit of such persons in belligerent countries or in neutral countries which have received belligerents in their territory. 4. Belligerents received and interned in a neutral country, as well as civilians of enemy nationality detained in civilian camps or prisons, are assimilated to prisoners of war properly so called, insofar as the application of the provisions mentioned above is concerned. ARTICLE 53. Internationalreply coupons. 1. International reply coupons are placed on sale in the countries of the Union. 2. Their selling-price is determined by the Administrations con- cerned, but may not be less than 28 centimes or the equivalent in money of the country selling them. Prisoners - of - war mail articles. 47 Stat. 2058.
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