This article comes from the free Global Sourcebook for International Data Management, here
An enclave is a piece of land which is totally surrounded by a foreign territory, and an exclave is one which is politically attached to a larger piece but not actually contiguous with it. There are many enclaves and exclaves in the world, caused by geographic, political and historical anomalies. In many cases their inhabitants, when there are any, share the same addressing forms and formats as the non-contiguous relation, but in a small number of cases its geography affects its addressing. Here is a summary of these cases. Some are covered in more detail in the relevant country chapter(s).
Armenia/Azerbaijan — In Armenia, there are three Azerbaijani exclaves. Barxudarlı and Yuxarı Əskipara are in north-eastern Armenia; Karki (renamed by Armenia to Tigranashen) is located north of the region of Nakhchivan. All of these enclaves are controlled by Armenia, inhabited mostly by Armenians, and use Armenian addressing.
There is an Armenian exclave, Artsvashen (Başkənd in Azeri) in north-western Azerbaijan. It is controlled by Azerbaijan, inhabited mostly by Azeris, and uses Azeri addressing.
Barxudarlı and Yuxarı Əskipara
Karki
Artsvashen (Source: Wikipedia)
Belgium/Netherlands — The town of Baarle the southern Netherlands is made up of the municipality of Baarle-Hertog, a group of 22 Belgian enclaves within the Netherlands; and of the Dutch municipality of Baarle-Nassau, which itself has one enclave in the main body of Belgium and 7 counter-enclaves inside two of the Belgian enclaves. Though streets usually have the same name in both countries, buildings are numbered, and the address system used, according to the country they are in (the position of the front door deciding this).
Source: Wikipedia
The border is shown here on the pavement with the hatching heading for the door of this residence.
The border between Belgium and The Netherlands runs through the front door of this house in Baerle-Hertog/Baerle Nassau. It has two numbers.
Germany — Büsingen, Germany is an exclave in the canton of Schaffhausen, Switzerland. It uses the German addressing structure and has a German postal code (78266), but because access to it is easier through Switzerland, it also has a Swiss postal code: 8238.
Italy— The town of Campione is an enclave in the canton of Ticino, Switzerland. It uses the Italian addressing structure and has an Italian postal code (22060), but because access to it is easier through Switzerland, it also has a Swiss postal code: 6911.
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