Excerpts from ICAO Annexe 10. .. .5.2.1.4.1.1 All numbers, except as prescribed in 5.2.1.4.1.2, shall be transmitted by pronouncing each digit separately.. .. .flight levels transmitted as. .FL 180 flight level one eight zero. .FL 200 flight level two zero zero. .. .5.2.1.4.1.2 All numbers used in the transmission of altitude, cloud height, visibility and runway visual range (RVR) information, which contain whole hundreds and whole thousands, shall be transmitted by pronouncing each digit in the number of hundreds or thousands followed by the word HUNDRED or THOUSAND as appropriate.. .. .Despite all that I rather like the idea of saying "flight level two hundred". I don't though, coz I'm not quite sure what an foreign flight might do... <img border="0" title="" alt="[Confused]" src="confused.gif" />