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They are agreed and published by a particular community of interest. There may be multiple versions of an exchange model e.g. IWXXM 1.1 was used by the SESAR programme but a v2.1 is now available and v3 is open for testingin pre-operations.
The exchange models listed above relate to three ICAO business domains (aeronautical, weather and flight information). However, other exchange models exist.
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