For historical reasons, Switzerland's official name is still the "Helvetic Confederation" (in Latin: Confoederatio Helvetica) from which the country's international abbreviation, CH, is derived. However, this is in fact a misnomer: a confederation is an alliance of autonomous entities. Since 1848 Switzerland has been a federation: a grouping of entities with a central authority.
CH -
ISO country code (ISO 3166-1 alpha-2,two letter)
Internet Country code top-level domain (ccTLD)
Distinguishing sign of vehicles in international traffic
CHE -
ISO country code (ISO 3166-1 alpha-3, three letter code)
SUI -
IOC country code
ITU letter codes for member-countries
SW -
WMO message header country code