CLDR 48 Release Note

No.	Date	Rel. Note	Data	Charts	Spec	Delta	GitHub Tag	Delta DTD	CLDR JSON
48	2025-10-XX	v48	CLDR48	Charts48	LDML48	Δ48	release-48	ΔDtd48	48.0.0

Overview

Unicode CLDR provides key building blocks for software supporting the world’s languages. CLDR data is used by all major software systems (including all mobile phones) for their software internationalization and localization, adapting software to the conventions of different languages.

CLDR 48 was an open submission cycle allowing contributors to supply data for their languages via the CLDR Survey Tool — data that is widely used to support much of the world’s software. This data is also a factor in determining which languages are supported on mobile phones and computer operating systems.

Changes

The most significant changes in this release are:

• TBD

For more details, see below.

Locale Coverage Status

Current Levels

Count	Level	Usage	Examples
xx	Modern	Suitable for full UI internationalization	…
xx	Moderate	Suitable for “document content” internationalization, eg. in spreadsheet	…
xx	Basic	Suitable for locale selection, eg. choice of language on mobile phone	…

Changes

±	New Level	Locales
📈	Modern	…
📈	Moderate	…
📈	Basic	…
📉	Basic*	…

* Note: Each release, the number of items needed for Modern and Moderate increases. So locales without active contributors may drop down in coverage level.

For a full listing, see Coverage Levels

Specification Changes

The following are the most significant changes to the specification (LDML).

• TBD

There are many more changes that are important to implementations, such as changes to certain identifier syntax and various algorithms. See the Modifications section of the specification for details.

Data Changes

DTD Changes

• territories attribute of languageData in supplementalData.xml removed. While it was a nice proxy to count the most important territories for each language, it was not clear and it was ripe for mis-understanding. (CLDR-5708)

For a full listing, see Delta DTDs.

Supplemental Data Changes

• language_script.tsv updated to include only one “Primary” writing system for languages that used to have multiple options (CLDR-18114). Notable changes are:
  • Panjabi pa has the primary to Gurumukhi Guru because widespread usage is in the Gurumukhi script – while most speakers are in Pakistan PK, written usage remains Gurumukhi.
  • Azerbaijani az and Northern Kurdish ku primarily are used in Latin Latn.
  • Chinese languages zh, hak, and nan are matched to Simplified Han writing Hans – except Cantonese yue, which is known for a preference in Traditional Han writing Hant.
  • Hassiniyya mey was missing significant data, it should be associated with the Arabic Arab writing system by default, not Latin Latn.
• Errors in likely subtags addressed
  • The default language for Belarus BY is now Russian ru, reflecting modern usage. (CLDR-14479)
  • Literary Chinese lzh was written in Traditional Han writing Hant. (CLDR-16715)
• Likely subtags updated because of prior mentioned primary script matches.
  • Northern Kurdish ku now matched to Cyrillic writing in the CIS countries. (CLDR-18114)
  • Hassiniyya mey updated to default to mey_Arab_DZ instead of mey_Latn_SN (CLDR-18114)
  • See other likely subtags updated in the Supplemental Data Delta page

For a full listing, see ¤¤BCP47 Delta and ¤¤Supplemental Delta

Locale Changes

• Kurdish (Kurmanji) ku split from 1 locale ku_TR into 5 locales across 2 scripts and 4 countries. (CLDR-18311)
  • ku_Latn_TR: Kurdish (Kurmanji, Latin alphabet, Turkey) default for Kurdish (Kurmanji) ku and ku_Latn
  • ku_Latn_SY: Kurdish (Kurmanji, Latin alphabet, Syria)
  • ku_Latn_IQ: Kurdish (Kurmanji, Latin alphabet, Iraq)
  • ku_Arab_IQ: Kurdish (Kurmanji, Arabic writing, Iraq), default for Kurdish (Kurmanji, Arabic writing) ku_Arab
  • ku_Arab_IR: Kurdish (Kurmanji, Arabic writing, Iran)

For a full listing, see Delta Data

Message Format Specification

• TBD

Collation Data Changes

• TBD

Number Spellout Data Changes

• TBD

Segmentation Data Changes

• TBD

Transform Data Changes

• TBD

JSON Data Changes

• TBD

File Changes

• TBD

Tooling Changes

• TBD

Keyboard Changes

• TBD

Migration

• TBD

V48 advance warnings

The following changes are planned for CLDR 48. Please plan accordingly to avoid disruption.

• Any locales that are missing Core data by the end of the CLDR 48 cycle will be removed CLDR-16004
• The default week numbering will change to ISO instead being based on the calendar week starting in CLDR 48 CLDR-18275. The calendar week data will be more clearly targeted at matching usage in displayed month calendars.
• The likely language for Belarus is slated to change to Russian CLDR-14479
• The major components in supplementalData.xml and supplementalMetadata.xml files are slated to be organized more logically and moved into separate files.
  • This will make it easier for implementations to filter out data that they don’t need, and make internal maintenance easier. This will not affect the data: just which file it is located in. Please plan to update XML and JSON parsers accordingly.
• Additionally, language and territory data in languageData and territoryInfo data will receive significant updates to improve accuracy and maintainability CLDR-18087

V49 advance warnings

• TBD

Known Issues

• CLDR-18219 common/subdivisions data files contained additional values that should not be present. These will be removed in the future, but note that they may be present in the new JSON data:
  • Non-subdivisions such as AW: Use the region code AW instead for translation.
  • Overlong subdivisions such as fi01: Use the region code AX instead for translation.

Acknowledgments

Many people have made significant contributions to CLDR and LDML; see the Acknowledgments page for a full listing.

The Unicode Terms of Use apply to CLDR data; in particular, see Exhibit 1.

For web pages with different views of CLDR data, see http://cldr.unicode.org/index/charts.