ART52 – 69 – ARTICLE 52 Special rules relating to the use of frequencies Section IV − Use of frequencies for digital selective-calling 52.110 A − General MOD 52.112 § 51 The characteristics of the digital selective-calling equipment shall be in accordance with Recommendation ITU-R M.541-10 and should be in accordance with the most recent version of Recommendation ITU-R M.493. (WRC-15) 52.141 D − Bands between 4 000 kHz and 27 500 kHz D2 − Call and acknowledgement MOD 52.149 2) The international digital selective-calling frequencies shall be as indicated in Recommendation ITU-R M.541-10 and may be used by any ship station. In order to reduce interference on these frequencies, they shall only be used when calling cannot be made on nationally assigned frequencies. (WRC-15) MOD 52.153 2) The international digital selective-calling frequencies shall be as indicated in Recommendation ITU-R M.541-10 and may be assigned to any coast station. In order to reduce interference on these frequencies, they may be used as a general rule by coast stations to call ships of another nationality, or in cases where it is not known on which digital selective-calling frequencies within the frequency bands concerned the ship station is maintaining watch. (WRC-15) Section VI − Use of frequencies for radiotelephony 52.176 A − General MOD 52.181 § 85 Single-sideband apparatus in radiotelephone stations of the maritime mobile service operating in the frequency bands allocated to this service between 1 606.5 kHz and 4 000 kHz and in the frequency bands allocated exclusively to this service between 4 000 kHz and 27 500 kHz shall satisfy the technical and operational conditions specified in Recommendation ITU-R M.1173-1. (WRC-15)