54 STAT.] MULTILATERAL-TELECOMMUNICATION-APR . 8 , 1938 sends traffic with all the necessary information in this connection, using for this purpose the appropriate abbreviations. ARTICLE 21 Use of Waves in the AMobile Service A. RESTRICTIONS (TYPE B AND BROADCASTING) [471] §1. (1) The use of type-B waves shall be forbidden in all radio mobe service n stations. [472] As an exception, it shall be permitted in ship stations on the following frequencies: 375 kc (800 m) for radio direction-finding only, 425 kc (706 m) for traffic, 500 kc (600 m). [473] (2) Mobile stations at sea shall be prohibited from making radiotelephone broadcast transmissions intended to be received by the general public. B. BAND OF 365-515 KC (822-583M) [474] §2. Calling and reply [475] (1) The general calling-wave which must be used by all ship stations and all coast stations working in radiotelegraphy in the authorized bands between 365 and 515 kc (822 and 583 m), as well as by aircraft wishing to enter into communication with a coast station or a ship, shall be the wave of 500 kc (600 m) (Al, A2, or B). [476] (2) In order to reduce interference in the regions of heavy traffic, the administrations reserve the right to consider that the re- quirements of paragraph (1) [No. 475] are satisfied if the calling-waves assigned to coast stations for the handling of public correspondence are not separated from the general calling-wave of 500 kc (600 m) by more than 5 kc. [477] (3) The wave for the reply to a call transmitted on the general calling-wave [see §2 (1)] [No. 475] shall be the wave of 500 kc (600 m), the same as that for calling. [478] §3. Distress [479] (1) The wave of 500 kc (600 m) shall be the international distress-wave; it shall be used for that purpose by ship stations and aircraft stations in requesting help from the maritime services. It may be used only for calls and replies, as well as for distress traffic, urgent and safety messages, and signals. [480] (2) By way of exception, this wave may nevertheless be used for traffic under the conditions indicated in §4 (3) below [Nos. 485, 486, and 487]. [481] (3) Aside from the wave of 500 kc (600 m), the use of waves of all types between 485 and 515 kc (620 and 583 m) shall be forbidden. 1523
�
