ICAO Annex 10, Volume II
5.3.3.1 Action by the aircraft reporting

5.2.3.2 an urgency condition except 5.2.3.2 as indicated in 5.3.3.4

5.3.3.1.1 In addition to being preceded by the radiotelephony urgency signal PAN PAN (see 5.3.1.2), preferably spoken three times and each word of the group pronounced as the French word “panne”, the urgency message to be sent by an aircraft reporting an urgency condition shall:

a) be on the air-ground frequency in use at the time;
b) consist of as many as required of the following elements spoken distinctly and, if possible, in the following order:

1) the name of the station addressed;
2) the identification of the aircraft;
3) the nature of the urgency condition;
4) the intention of the person in command;
5) present position, level (i.e. flight level, altitude, etc., as appropriate) and heading;
6) any other useful information.