Table BBB

WMO>WWW >WWW Operational Information Service (OIS)> Telecommunications Abbreviated Heading - TAAii CCCC

Explanation of Data Designators T1T2A1A2ii CCCC

INSTRUCTIONS FOR THE USE OF THE INDICATOR BBB

Instructions for the proper application of the data type designators

1. The BBB indicator shall be included in the abbreviated heading lines of additional, subsequent, corrected or amended bulletins by those centres which are responsible for preparing or compiling the bulletins concerned.

2. The BBB indicator shall be added when the abbreviated heading line defined by T1T2A1A2ii CCCC YYGGgg has already been used for the transmission of a corresponding initial bulletin. Once the initial bulletin has been transmitted, the centre responsible for preparing or compiling the bulletin uses the BBB indicator to transmit additional, subsequent corrected or amended messages for the same T1T2A1A2ii CCCC YYGGgg, but appended with the appropriate form of BBB indicator, following these guidelines:

(a)	To transmit information or reports normally contained in an initial bulletin after the initial bulletin has been transmitted or for a subsequent or additional issuance of a bulletin whose T1T2A1A2ii CCCC YYGGgg would not be unique without a BBB fi eld and CCx or AAx does not apply. The BBB indicator to be used is RRx, where x =:
	A, for the first bulletin after the issuance of the initial bulletin; B, if another bulletin needs to be issued; and so on up to and including x = X;
(b)	To transmit a bulletin containing corrected information or reports that have already been issued in a previous bulletin. The BBB indicator to be used is CCx, where x =:
	A, for the first bulletin containing corrected reports or information; B, if a second bulletin containing corrected reports or information is issued; and so on up to including x = X;
(c)	To transmit a bulletin containing amendments to the information included in a previously issued bulletin. The BBB indicator to be used is AAx, where x = :
	A, for the first bulletin containing amendments to information; B, for a second bulletin containing amendments to information; and so on up to and including x = X;
(d)	If more than 24 BBB indicators have to be used for the sequences detailed in (a), (b) and (c) above, then x = X should continue to be used;
(e)	For (a), (b) and (c) above, the characters x = Y and x = Z are to be used for special purposes indicated below:
	(i)	x = Y should be used for the encoding of BBB when a system failure causes loss of the record of the sequence of character values assigned to x;
	(ii)	x = Z should be used for the encoding of BBB when bulletins are prepared or compiled more than 24 hours after the time of observation.

3. An RTH on the GTS should ensure the relay of the bulletins received in accordance with its routeing directories even if the bulletins containing BBB indicators have not been received in the correct sequence.