Quotation from the "Handbuch Seefunk" from May 1981:
b) TR information, ETA and ETS reports
(2) Coastal radio stations can use the abbreviation TR to request maritime radio stations to transmit the following information:
– the ship’s name
– the location and, if possible, the route and the speed;
– the next port of call.
The maritime mobile radio stations should, whenever appropriate, transmit such TR information on their own initiative, i.e. without special request; especially if they come into the traffic area of a coast station.
TR information is only transmitted after the ship’s command has given its approval.
(3) Every maritime mobile station must notify the nearest coast radio station when the ship enters or leaves a port. If possible and expedient, the other coast radio stations with which the marine radio station generally operates should also be informed. In doing so, the regulations of the country concerned about sending in its territorial waters must be observed.
The abbreviation TR is also used to announce incoming and outgoing messages.
(4) Examples of Paragraphs 2 and 3:
- Radio telegraphy:
TR Clio/DAKQ QTH Norderney fm Bremen bnd Rotterdam.
Meanings: Clio/DAKQ – Ship's name und callsign QTH - Position of the transmitting station, here Norderney fm Bremen – from Bremen bnd Rotterdam – bound Rotterdam
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