languagelocale

Languagelocale is a term used in software internationalization to denote a combined language and regional setting that determines both the language of user interface text and the cultural conventions used to present data. It serves as a key context for selecting translations and formatting rules in applications.

In practice, a languagelocale is typically expressed as a language tag that follows standards such as IETF BCP 47. Common forms include language codes plus region codes, for example en-US (English as used in the United States) or fr-CA (French as used in Canada). Some systems accept alternate spellings with an underscore, such as en_US, but the hyphen form is preferred for interoperability. More detailed tags can include script information, such as zh-Hans-CN for Simplified Chinese as used in China.

The purpose of a languagelocale is twofold: linguistic content and locale-specific formatting. It selects translations for strings and user-visible text, and it also governs conventions for date and time formats, number and currency formatting, sorting rules, and sometimes input methods. This helps ensure that users see content in their language and in a familiar cultural format.

Implementation and use vary by platform. Many frameworks provide locale-aware APIs, with fallbacks if a requested languagelocale is unavailable. Best practices include canonicalizing inputs to a standard form, implementing sensible fallbacks, and clearly communicating the active languagelocale to users.

See also: ISO 639 language codes, ISO 3166 country codes, IANA language tags, internationalization, localization.