NOTAM is a notice distributed by means of telecommunication containing information concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to personnel concerned with flight operations. The text of each NOTAM contains the information in the order shown in the ICAO NOTAM format and is composed of the significant or uniform abbreviated phraseology assigned to the ICAO NOTAM code complemented by ICAO standard abbreviations, indicators, identifiers, designators, call signs, frequencies, figures and plain language. NOTAM are originated and issued for Manila FIR and are distributed in two series identified by the letters B and C.