7754 Vol 2 Flyleaf - ICAO Public Maps

CNS
IV-A3
Note 6.— See Note 2.
Note 7.— The first two letters constitute the category
identifier; the second two letters indicate the State or
MOTNE area of origin; the two figures constitute the
number used to differentiate two or more bulletins which
contain data in the same code, which originate from the
same State or MOTNE area, and have the same originating
centre. They are chosen from the series “31, 32 ...”. (See
also WMO Manual on the GTS; Volume 1, Part II.)
Note 8.— Four-letter location indicator of the station
originating or compiling the bulletin.
Note 9.— One figure shift (Signal 30) to place receiving
machines in the figures case.
Note 10.— A six-figure group where:
a) in the case of routine reports and selected special reports,
the six figures are the date/time group of the instant that
the meteorological observations were made;
b) in the case of aerodrome forecasts, the group comprising
the day of the month followed by the rounded UTC hour
preceding the MOTNE loop scheduled transmission time
for the bulletin concerned;
c) in the case of SIGMET messages, special air reports,
loop breakdown messages and notices, the six figures
are the date/time group of the instant of filing;
N.B. The following examples are given for
demonstration purposes only and do not correspond
to the current situation as regards to the exact
contents of the bulletins.
d) in the case of corrected, amended or delayed messages,
the six figures should be the same as in the original
bulletin.
Note 11.— Optional elements, including:
— one space (Signal 31);
— one letter shift (Signal 29);
— additional indicator (AAA, AAB, AAC, etc., or CCA,
CCB, CCC, etc. or RRA, RRB, RRC, etc.), used in
conformity with 20, 21 or 22;
— one figure shift (Signal 30).
EXAMPLE 1
Starting pulse < < ZCZC