here what is written in annex 10:
5.3.3.4.2 For the purpose of announcing and identifying
aircraft used for medical transports, a transmission of the
radiotelephony urgency signal PAN PAN, preferably spoken
three times, and each word of the group pronounced as the
French word “panne”, shall be followed by the radiotelephony
signal for medical transports MAY-DEE-CAL, pronounced as
in the French “médical”. The use of the signals described
above indicates that the message which follows concerns a
protected medical transport. The message shall convey the
following data:
a) the call sign or other recognized means of identification
of the medical transports;
b) position of the medical transports;
c) number and type of medical transports;
d) intended route;
e) estimated time en route and of departure and arrival, as
appropriate; and
f) any other information such as flight altitude, radio
frequencies guarded, languages used, and secondary
surveillance radar modes and codes.
maybe this answers the initial question