DEAT

deAT is a locale identifier used in computing to denote German as used in Austria. In the standardized form defined by BCP 47, the canonical tag is de-AT. Some software and documentation also refer to a concatenated form deAT to indicate the same language-country combination, particularly in file names, code variables, or domain-specific tag schemes where hyphens are disallowed.

In software localization, de-AT governs language translations, keyboard layouts, and regional conventions. Typical Austrian German usage includes date formats in day-month-year with periods, the decimal separator as a comma, currency as the euro, and the 24-hour clock in most official contexts.

Austria-specific variants affect vocabulary and orthography; translations may differ from de-DE (Germany) or de-CH (Switzerland). The de-AT locale thus helps tailor user interfaces, help texts, and resources to Austrian users.

Origin and standardization: The concept follows the broader language-country codes used in ISO 639-1 (de) and ISO 3166-1 alpha-2 (AT). In computing, BCP 47 assigns de-AT as the preferred tag; deAT appears as a noncanonical form in some systems. The usage is common across operating systems, web platforms, and development frameworks to enable Austrian-specific localization.

See also: de-DE, de-CH, locale, BCP 47.