In the US, the first digit of the ZIP code indicates how far the location is from the East Coast. Hence, postal codes in New York start with 1, while along the entire West Coast (California, Oregon, Washington) they begin with 9.
In Russia, the first digit of the postal code is formed as if tracing the borders in a counterclockwise direction starting from the north. Nearly all the territory is covered by postal codes starting with 6. Codes starting with five are designated for international mail reception points abroad. I failed to find anything about them except for code names – Tskhinvali, South Ossetia (postal code 500200), London (500380), Newark, USA (500380), Virolahti, Finland (500580), Basildon, England (500680), Singapore (500780), Altanbulag (500880), Folcroft (500980).
Tskhinvali: “…Following the signing of the Memorandum, ‘Post of Russia’ used its own funds to restore the main post office destroyed in August 2008 in the South Ossetian capital of Tskhinvali, equipping it with all necessary equipment, furniture, computers. The same services that are available in any modernized Russian post office are accessible at this branch,” noted Kotov.”
Altanbulag: “…In September 2019, a Strategic Cooperation Agreement was signed between FSUE ‘Post of Russia’ and JSC ‘Mongol Post’.”
Apparently, all these “international mail reception points abroad” are just virtual. I was unable to find anything physical.
While researching, I found that the Russian post was active in China from 1870 to 1920, in Crete from May 13 to July 29, 1899, and even in the Ottoman Empire.
Hi, I'm Rauf Aliev. 