See Also: RegionInfo Members
The name of a System.Globalization.RegionInfo object is one of the two-letter codes defined in ISO 3166 for country/region. Case is not significant. The RegionInfo.Name, RegionInfo.TwoLetterISORegionName, and RegionInfo.ThreeLetterISORegionName properties return the appropriate codes in uppercase. For the current list of System.Globalization.RegionInfo names, see tp://go.microsoft.com/fwlink/?LinkId=190591 on the ISO website.
To instantiate a System.Globalization.RegionInfo object, you pass the RegionInfo.#ctor(string) constructor either a two-letter region name, such as "US" for the United States, or the name of a specific culture, such as "en-US" for English (United States). However, we recommend that you use a specific culture name instead of a two-letter region name, because a System.Globalization.RegionInfo object is not completely language-independent. Several System.Globalization.RegionInfo properties, including RegionInfo.DisplayName, RegionInfo.NativeName, and RegionInfo.CurrencyNativeName, depend on culture names.
The following example illustrates the difference in System.Globalization.RegionInfo property values for three objects that represent Belgium. The first is instantiated from a region name (BE) only, while the second and third are instantiated from culture names (fr-BE for French (Belgium) and and nl-BE for Dutch (Belgium), respectively). The example uses reflection to retrieve the property values of each System.Globalization.RegionInfo object.
code reference: System.Globalization.RegionInfo#2
In scenarios such as the following, use culture names instead of country/region names when you instantiate a System.Globalization.RegionInfo object:
When the language name is of primary importance. For example, for the es-US culture name, you'll probably want your application to display "Estados Unidos" instead of "United States". Using the country/region name (US) alone yields "United States" regardless of the language, so you should work with the culture name instead.
When script differences must be considered. For example, the country/region AZ deals with Azerbaijani cultures that have the names az-Latn-AZ and az-Cyrl-AZ, and the Latin and Cyrillic scripts can be very different for this country/region.
When maintenance of detail is important. The values returned by System.Globalization.RegionInfo members can differ depending on whether the System.Globalization.RegionInfo object was instantiated by using a culture name or a region name. For example, the following table lists the differences in return values when a System.Globalization.RegionInfo object is instantiated by using the "US" region, the "en-US" culture, and the "es-US" culture.