from User talk Tobias Conradi Hello Tobias Thought you d like to know I ve recently concluded a useful email correspondence with a member of staff at the US National Geospatial Intelligence Agency NGA In short it appears the NGA uses a four to five level system not unlike NUTS LAU I ve transcribed it from the table sent by email into the wikitable below Feature Designation Code Name Text ADM1 first order administrative division a primary administrative division of a country such as a state in the United States ADM2 second order administrative division a subdivision of a first order administrative division ADM3 third order administrative division a subdivision of a second order administrative division ADM4 fourth order administrative division a subdivision of a third order administrative division ADMD administrative division an administrative division of a country undifferentiated as to administrative level The NGA leaves the definitions Text in the above table of ADMs 2 4 intentionally vague All we attempt to identify with the ADM is the hierarchical structure and if there is no hierarchy then the level of importance or size with ADM1 being the largest In a table of global country subdivisions would you expect all those entities found in a particular column i e at a particular level to be similar in importance or size presumably where size might mean area or population Regards