Station code
A station code is a brief, standardised abbreviation, or alphanumeric code, used by railways to identify a railway station uniquely (within a country or region). Codes are mostly used internally but can be seen on railway traffic signs and on some timetables. In most countries, station codes are purely alphabetic, usually compromising a few capital letters for ease of identification, in some countries one capital and one or some lowercase letters. Americas

United States

Amtrak encodes a few stations in Canada which it serves. Asia

Hongkong

A three-letter code system is in use in the MTR to identify stations. For example, Whampoa station of the MTR has the code of WHA. India

Indian Railways uses one- to four-letter codes. Most stations of the Indian Railways are assigned three letter codes, for example, the station code for Mumbai Central station is BCT and for Guwahati is GHY. One-letter station codes of the Indian Railways

 G: Gondia Junction railway station
 J: Jalna railway station
 R: Raipur Junction railway station
 S: Shrirangapattana railway station
 Y: Yeliyur railway station
 Unallocated one-letter station codes of the Indian Railways include A, B, C, D, E, F, I, H, K, L, M, N, P, Q, T, U, V, W, X and Z. South Korea
In South Korea, station codes are purely numeric, to reduce the problem of language and writing system barriers. For example, Seoul Metropolitan Subway's Singeumho station has the code of 538. Europe

Denmark and Sweden

In Sweden and Denmark, railway stations are assigned a capital letter followed by a sequence of lowercase letters that represent the station's name. For example, Stockholm commuter rail's Stockholm City Station has the station code Sci. In Sweden the code is in a few cases a single capital letter, such as M for Malmö Central Station. Germany

Deutsche Bahn in Germany uses an alphabetic station code system called the DS 100 code, for example, Luckenwalde station in Brandenburg has the station code BLD. Norway
Stations normally have a code of three capital letters, sometimes two letters. They are called "stedskoder" (location codes). Examples: OSL=Oslo Central Station, GAR=Oslo Airport Station, TND=Trondheim Central Station and BO=Bodø Station. UK
 Three-letter alpha codes (formerly called CRS codes - Computer Reservation System) are issued by National Rail which is responsible for railways in Great Britain. Station codes are not used by Northern Ireland Railways for stations in Northern Ireland. In England, Scotland and Wales of the UK, railway stations are assigned three-letter codes and are issued by National Rail and are called the Computer Reservation System (CRS), this is not the case in Northern Ireland. See also
 Station numbering

References

Railway stations