Article 9 - Electronic identification
1. The Secondary Surveillance Radar (SSR) system, as specified in Annex 10 to the Chicago Convention on International Civil Aviation of 7 December 1944, as amended from time to time, may be used to identify and to follow the course of medical aircraft. The SSR mode and code to be reserved for the exclusive use of medical aircraft shall be established by the High Contracting Parties, the Parties to a conflict, or one of the Parties to a conflict, acting in agreement or alone, in accordance with procedures to be recommended by the International Civil Aviation Organization.
2. Protected medical transports may, for their identification and location, use standard aeronautical radar transponders and/or maritime search and rescue radar transponders.
It should be possible for protected medical transports to be identified by other vessels or aircraft equipped with secondary surveillance radar by means of a code transmitted by a radar transponder, e.g. in mode 3/A, fitted on the medical transports.
The code transmitted by the medical transport transponder should be assigned to that transport by the competent authorities and notified to all the Parties to the conflict.
3. It should be possible for medical transports to be identified by submarines by the appropriate underwater acoustic signals transmitted by the medical transports.
The underwater acoustic signal shall consist of the call sign (or any other recognized means of identification of medical transport) of the ship preceded by the single group YYY transmitted in morse on an appropriate acoustic frequency, e.g. 5kHz.
Parties to a conflict wishing to use the underwater acoustic identification signal described above shall inform the Parties concerned of the signal as soon as possible, and shall, when notifying the use of their hospital ships, confirm the frequency to be employed.
4. Parties to a conflict may, by special agreement between them, establish for their use a similar electronic system for the identification of medical vehicles, and medical ships and craft.