They are typically 1, 2, 3, or 4 character combinations (referred to as unigrams, digrams, trigrams, or tetragrams, respectively) that uniquely identify locations, equipment, companies, and times to standardize international flight operations.
All codes within each group follow a pattern (same number of characters, and using either all letters or letter/digit combinations) to reduce the potential for error.
IATA time zone code is constructed of 2–4 characters (letters and digits) as follows: Example: Time zone code AU2 is used for Australian states New South Wales and Victoria (local time is UTC + 10 hours, DST begins at end of October).
For all other purposes only country code RU is used to specify all the territory of Russia.
IATA Cabin Operations Safety Best Practices Guide - 19.7 Special Meals Archived 2021-11-14 at the Wayback Machine defines the following standard meal codes: Codes used by other airlines include: The trigram is composed of the first letter of first name and the first two letters of the names (ISO 9625) IATA class codes are 1-letter codes created to help airlines standardize conditions of travel on passenger tickets and other traffic documents.