63 STAT.] MULTILATERAL-TELECOMMUNICATIONS-OCT. 2, 1947 (Chapter Xm, art. 29 RR) (604-612) 604 (3) Aircraft stations when communicating with sta- tions of the maritime mobile service must use the procedure laid down in this article. 605 §2. The use of the Morse code signals specified in the Telegraph Regulations shall be obligatory in the maritime Ante, p. 1431n. and aeronautical mobile services. However, for radiocommu- nications of a special character, the use of other signals is not precluded. 606 § 3. (1) In order to facilitate radiocommunications, stations of the mobile service use the service abbreviations given in appendix 9. 607 (2) In the maritime mobile service, only the service abbreviations given in appendix 9 are to be used. 608 §4. The provisions of §§ 6, 23, 24 and 25 of this article are applicable to radiotelephone communications in the mobile service. Section I1. Preliminary Operations 609 §5. In areas where traffic is congested, ship stations must take into account the provisions of 721. 610 § 6. (1) Before emitting, every station must listen for a period long enough to satisfy itself that it will not cause harmful interference to transmissions in progress within its range; if such interference is likely, the station awaits the first break in the transmission with which it might interfere. 611 (2) If, these precautions having been taken, the emis- sions of the station happen to interfere with a radio trans- mission already in progress the following rules are to be applied: 612 a) Within the zone of communication of a coast station open to public correspondence or of any aeronautical station, the station whose emission causes the interference must cease sending at 1827
�
