Form of acknowledgement.

(a) The acknowledgement of receipt of a radiotelegraph distress message is transmitted in the following form: (1) The distress signal SOS; (2) The call sign of the station sending the distress message, sent three times; (3) The word DE; (4) The call sign of the station acknowledging receipt, sent three times; (5) The group RRR; (6) The message signal SOS. (b) The acknowledgement of receipt of a radiotelephone distress message is transmitted in the following form: (1) The distress signal MAYDAY; (2) The call sign or other identification of the station sending the distress message, spoken three times; (3) The words THIS IS; (4) The call sign or other identification of the station acknowledging receipt, spoken three times; (5) The word RECEIVED; (6) The distress signal MAYDAY.