ICAO SARPS (Standards and Recommended Practices) for each area of ICAO responsibility are contained in 19 Annexes. These documentations are published since 1944, these standards enable Pilots to fly across the world using a common language (English) for communication especially in air traffic control and using the Same Navigational aids (VOR, DME, ILS, NDB), designations of airways and runways rather than developing a new standard. Each Annex deals with a particular subject area. All are subject to regular amendment and the detail in respect of many of them is contained in publications in the numbered ICAO Document Series.