Practical International Data Management - Administrative districts
Administrative districts appear in the postal addresses of some countries, and may be stored for other countries to aid in certain data manipulaion processes. This data can be standardised.
Large numbers of countries in the world do not include an administrative district (state/provice etc.) in a postal address.
Not every place in the world is part of an administrative district.
It is a fallacy to assume that administrative districts can be assigned on the basis of postal code or vice versa. They have different purposes, and more often than not their borders are not shared. A postal code area may straddle more than one administrative area, and vice versa. Given the number of business which still try to force a postal codes neatly into administrative areas, this is important to bear in mind.
Administrative districts of different levels may have borders which overlap. They do not necessarily neatly fit into each other.
Administrative districts hierarchies within countries may differ by region.
Example: Canada. Administrative distric hierarchies differ by province/territory
Administrative districts are dynamic. They change names, extent, borders; the appear and disappear.
No (non-dynamic) form to collect an address from an international audience should require the input of an administrative district, such as a state. Ideally this should be requested only for those countries whose addresses have an administrative district, based on the country that the customer has provided.