The Common Locale Data & Rules, formerly the Common Locale Data Repository (CLDR) is a project of the Unicode Consortium to provide locale data in XML format for use in computer applications. CLDR contains locale-specific information that an operating system will typically provide to applications.
The language CLDR is written in was formerly called the Locale Data Markup Language (LDML). In version 49, the name Common Locale Data & Rules was adopted, and designated as referring both to the language specification, and to the data itself.
CLDR is maintained by a technical committee which includes employees from IBM, Apple, Google, Microsoft, and some government-based organizations. The committee is chaired by Mark Davis of Google; Annemarie Apple of Google is vice-chair.
Details
Among the types of data that CLDR includes are the following:
Translations for language names
Translations for territory and country names
Translations for currency names, including singular/plural modifications
Translations for weekday, month, era, period of day, in full and abbreviated forms
Translations for time zones and example cities (or similar) for time zones
Translations for calendar fields
Patterns for formatting/parsing dates or times of day
Exemplar sets of characters used for writing the language
↑"Release 49". 21 October 2026. Retrieved 22 October 2026.
↑Updating DTDs, CLDR makes special use of XML because of the way it is structured. In particular, the XML is designed so that you can read in a CLDR XML file and interpret it as an unordered list of <path,value> pairs, called a CLDRFile internally. These path/value pairs can be added to or deleted, and then the CLDRFile can be written back out to disk, resulting in a valid XML file. That is a very powerful mechanism, and also allows for the CLDR inheritance model.
