CLDR 26 Release Note


Version 26 added significant new data, with 77 locales now reaching the 100% modern coverage level (see §4 Coverage). Collation data was reorganized to use the new import feature, resulting in about 23% less source data. Overall there was a growth of about 20% in data.

Changes include the following:

  • Units: Added 72 new units, added display names for all units and a new perUnitPattern (eg, liters per second).

    • Collation: Updated collation (sorting) to Unicode 7.0, moved Unihan radical-stroke collation into root to avoid duplication, used import to reduce source size by 23% and ease maintenance. Major changes to Arabic collation.

    • Spell-out numbers: improvements for round-trip fidelity; new syntax for use of plural categories.

    • Specification: documented new structure, \x{h...h} syntax for Unicode code points; construction of “unit per unit” formats; clarified BCP47 and Unicode identifiers, and different kinds of locale lookup, matching, and inheritance. For more info, see Modifications.

    • Survey Tool: Major improvements to the UI to make it easier and faster to enter and check data.

A major goal for the release was improving the submission tool UI to make it easier for people to enter data, and to flesh out more of the measurement units.


The new/changed data were items that appeared in the release, after reconciling votes from different submitters. The number is thus lower than the number of submissions.

The table at the top of this page lists the files for this release. For a description of their purpose and format, and for the coverage graphic, see the Key. For a full list of ticketed changes, see the Delta link in the table above. Most translation data is entered in through the Survey Tool, and isn't ticketed.

Structural additions and changes


For more information see Unit Elements (LDML spec) and Units (Translation Guidelines).

Under <unitLength type=“xx”><unit type=“xx”>, added the following

    • <displayName> element providing a display name of the given length type for the given unit (eg, centimeters).

    • Optional <perUnitPattern> element such as “{0} per hour” as an option (depending on grammar requirements) for constructing compound units such as “4.5 cm per hour”. [#6020]

Added 72 more unit types (beyond the 49 in CLDR 25) and data for them [#7214]:


    • Under <numbers>, add <minimumGroupingDigits>. This can be used to indicate whether the locale suppresses grouping separators (such as thousands separators) below a certain value, so that for example the grouping separator is only used for values of 10000 and up. See Number Elements (LDML spec) and Numbering Systems (Translation Guidelines).

    • Under <numbers>/<symbols>, add <timeSeparator>. This replaces any use of ":" in a date-time format pattern, which allows the same time format to be used for multiple number systems. For example, the time format for Arabic should be colon when using the Latin numbering system, but comma when using the Arabic numbering system. [#4254]


  • RBNF (spelling out numbers, such as “twenty-two”) can now make use of plural categories, allowing the rules to be more general and simpler, for example "$(ordinal,one{st}two{nd}few{rd}other{th})$" or "$(cardinal,one{миллион}few{миллионы}other{миллионов})$". The relevant syntax is defined by ICU and is documented in the RuleBasedNumberFormat class documentation. [ICU #10880, #11064]


    • Under <cyclicNameSets>, added <cyclicNameSet type="solarTerms”> for the 24-name cycle of major and minor solar terms used in the Chinese lunar calendar, e.g. “spring begins”, “rain water”, “insects awaken”, “spring equinox”, ... [#7285]

    • Under <fields>:

      • Added <field type=“quarter”> for e.g. “last quarter”. [#6042]

      • Added -short and -narrow versions of most existing types (year, month, week, day, hour, minute, second, and the days sun..sat), for e.g. “3 secs. ago” or “3s ago”. [#6702]

    • In date/time patterns, ':' can now act as a pattern character; if the number symbols for the number system in effect include a <timeSeparator> element, then the value of that element replaces the ':'; otherwise, the literal ':' is used. [#4254]


    • The <collation> element "visibility='internal'" attribute-value has been deprecated. Collations have external visibility by default; a collation whose type name starts with "private-" is internal. For example, this can control which collations are displayed in a list of collation options for users to choose from. [#3949]


    • Under <segmentation>, the <exceptions> element introduced in CLDR 24 has been deprecated and replaced with the <suppressions> element, which takes a type attribute, typically as <suppressions type="standard”>. [#7237]


    • Under supplemental <codeMappings>, added <currencyCodes> table mapping ISO 4217 3-letter currency codes to numeric codes. [#4764]

    • For the <languageAlias> element, the reason attribute supports additional values including the new "bibliographic".

Data additions and changes

Aside from the large volume of additional data gathered through the survey tool (see Coverage), the following specific changes have been made.


  • Changed fr_CH thousands separator to space. [#7238]

  • For Thai, changed symbol for THB from "฿" to "THB". [#7618]

  • For pt_PT, pt_CV, kea: Change currency formats for Escudo so the currency symbol is the decimal separator, e.g. "1,234$56". [#7670]


  • English ordinal rules now round-trip (format → parse recovers value) [#7829]

  • Russian, Polish and Belarusian now properly format and parse the numbers larger than 1000. [#5879, #6774, #7344, #7680]

  • Other fixes for Indonesian, Ethiopic, and Spanish (Replaced many regional-variant rules with es_003.xml). [#6994, #7204, #6799]

  • For German, added many inflected forms. [#7384]

Times and dates

  • Added availableFormats item for skeleton "E", typically mapping to pattern "ccc". [#7236]


  • Added new metazone "Apia" (Independent State of Samoa) and "Europe_Further_Eastern" (year-round UTC+3 zone in Russia and Belarus). [#7530][#7317]

  • The English name for daylight time in the "Europe/Dublin" zone is changed from "Irish Summer Time" to "Irish Standard Time". [#10076]

  • In French, for summer time use “heure d’été “ instead of “heure avancée”. [#7717]

  • Also see BCP47 changes below.

Other display names

  • Many new language names in English, mostly for use by Microsoft or

  • Additional Script names and metadata for the new Unicode 7.0 scripts

  • Shortened English display names for some regions (e.g. from "Saint Barthélemy" to "St. Barthélemy") [#7777]


    • Updated to Unicode 7.0. The root collation covers all new scripts and characters. [#7195]

    • Added import statements to reduce source size and improve maintenance. [#4246]

    • Revised search collators to import root search data rather than duplicating its rules. [#6578]

    • The root collation data files include data for Unihan radical-stroke order; and most of the mappings were removed from CJK type="unihan" tailorings, because they now can assume that the root collation order sorts Han characters in Unihan radical-stroke order.[#7176]

    • Major changes to Arabic collation. The previous collation is available as type="compat". Full details are available as comments in the collation source. [#4207]

    • Small changes to collation sequences for Danish, Finnish, Estonian, Maltese, and Malayalam. [#6615, #6701, #7023, #7031, #7486]


    • Expanded the number of locales with plural ranges to 73 (af, am, ar, az, bg, bn, bs, ca, cs, cy, da, de, el, en, es, et, eu, fa, fi, fil, fr, gl, gu, he, hi, hr, hu, hy, id, is, it, ja, ka, kk, km, kn, ko, ky, lo, lt, lv, mk, ml, mn, mr, ms, my, nb, ne, nl, pa, pl, pt, ro, ru, si, sk, sl, sq, sr, sv, sw, ta, te, th, tr, ug, uk, ur, uz, vi, zh, zu)

  • Added ordinals for 3 locales [bs, dsb, hsb], and cardinals to 2 locales [dsb, hsb]. Modifications for 2 locales.


  • Updated the segmentation suppressions with new data from ULI for de, en, es, fr, it, pt, ru. [#10745]


  • The Lithuanian casing transforms (lt-Lower, lt-Title) are fixed to match the Unicode file SpecialCasing.txt [#7039]

  • Latin-Bopomofo no handles 'v' correctly. [#7598]


  • Many new likely subtags; the generation also now ensures idempotency (within certain constraints)

  • The language matching fallback for Lao changed to English.

  • Some additions and fixes to "official" languages, populations, and literacy data.

  • Made islamic-umalqura be the preferred islamic calendar in Saudi Arabic and 4 nearby countries. [#7592]

  • Updated weekend data for Algeria, Iran, Oman. [#10859]


  • Added; now used to convert Zawgyi into Unicode when data is input. [#6977]

  • Almost all data now exported to ICU with the NewLDML2ICUConverter, including all bcp47 data, plus supplemental and alternates [#7808]

  • Updated scriptMetadata for new scripts in Unicode 7.0. [#6762]


The following shows the additional coverage in this release. The horizontal axis shows the number of languages. The area between lines are the additional data added in that release. The axis shows the percentage of modern coverage, as measured for the v26 definition.

The definition of “modern coverage” increases over time, as new structure and requirements are added. This chart is using the most recent definition, but applying it to previous versions. In late 2009 we introduced the coverage levels, and thus the data starts to hit certain plateaux, one at 100% and one at around 30%.The plateaux tend to “slump” because of plurals; that is, when a new field with plurals is introduced, it counts as 1 missing string in Japanese (with only one plural form), and 6 missing strings in Arabic (with six plural forms).

For consistency, the current versioning convention is applied to versions 2.0 and previous; thus they appear as 20, 19, etc. The odd-numbered versions (25, 23, ...) tend to be consolidation releases, which don't have a major data submission phase. Some languages don't quite hit 100% because of the way coverage is measured.

The following chart shows the coverage levels for v26. The definition of the various levels of coverage increases over time, as new structure and requirements are added. Three different coverage levels are shown in the chart, from modern down to basic. The light lines show where data is available, but unconfirmed.


The version 26 Charts have been updated for the new data. There were some refinements to the locale data charts, where all the regional locale values that are different are shown in the Sublocales column, on the same row in the main language chart, such as for Spanish [es].

Specification changes

The specification changes are detailed in LDML Modifications. Other than documentation of the new structure, there was a reorganization of Section 3 to make the information about BCP47 extensions more accessible, and there were many clarifications to the documentation: For example regarding BCP47 and Unicode identifiers; different kinds of locale lookup, matching, and inheritance; \x{h...h} syntax for Unicode code points; construction of “unit per unit” formats.

BCP47 changes

  • Deprecated key "kh" (collation parameter for special Hiragana handling).

  • Added collation ("co") type value: "compat"

  • Added timezone ("tz") type values: "aqtrl" (Antarctica/Troll), "ruchita" (Asia/Chita), "rusred" (Asia/Srednekolymsk)

  • Deprecated timezone ("tz") type values: "cnckg" (use "cnsha"), "cnhrb" (use "cnsha"), "cnkhg" (use "cnurc")

Changes to JSON structure and data

No significant structural changes to the JSON data. All JSON data has been regenerated to correspond to the XML as published in the 26 release.

Survey Tool

  • Completely redesigned user interface - including a new "dashboard" feature that allows the user to "fix" problem areas

  • Ability to hide items already investigated

  • CSS webfont support for improving display of some languages

  • Improved many of the forum features, including multi-thread support for forum discussions.

  • Ability to flag high visibility items for CLDR TC review

  • Improvements to show differences between related sublocales ( such as de_DE vs. de_CH )

  • Many performance enhancements.

Migration issues

The main "pain points" for migration have typically been changes in:

  • plural forms: since the categories are used for translation of system or application messages, and may require retranslation.

  • collation: because if sort keys are stored in a database, the database requires reindexing.

  • date/time/number formatting: typically only because of "Golden Data" tests; where people store a snapshot of formatted dates (for example), and compare results against that snapshot.

Changes to plural/ordinal rules

Cardinals (0, 1, 2, …)

  • Portuguese (default = Brazilian) changes the plural category of 0 to singular (one).

  • This should not require retranslation, except where messages mask "one" with the explicit "=1", and where the message allows for zero 0 items (not "unused plural form").

Ordinals (1st, 2nd, …)

  • Ukrainian introduces the category few for 3,23,33,43,53,63,73,83,93...

  • This would require retranslation to add the messages for few, but only with ordinals, not cardinals.

Changes to Collation

Collation has changed for Unicode 7.0, but also some small changes in certain languages. There is a major change in Arabic; the previous comparison is preserved for now under the tag "compat". See below for details.

Changes in Date/Time/Number formatting

    • Changed fr_CH thousands separator to space. [#7238]

    • For Thai, changed symbol for THB from "฿" to "THB". [#7618]

    • nb/nn short date format changed from "dd.MM.yy” to "dd.MM.y" [#7778]

    • es_US, changed date formats to match es [#10787]

    • th, add era G to gregorian date formats [#7784]

    • Lithuanian date formats: use nominative month name LLL+ when the format does not include day number, avoid abbreviated month names (use numeric for medium format). [#7580, #6909]

  • The English name for daylight time in the "Europe/Dublin" zone is changed from "Irish Summer Time" to "Irish Standard Time". [#10076]

  • In French, for summer time use “heure d’été “ instead of “heure avancée”. [#7717]

Other Data changes

In the English locale, there were two changes that may require changes in Golden Data tests:

  • “South-Eastern Asian” changed to ”Southeast Asia”

  • Some country names changed for more consistent use of & and St.

  • Replaced generic quotes ' and " by curly quotes “”‘’, or sometimes the letter modifier U+02BC.


    • The Release Note contains a general description of the contents of the release, and any relevant notes about the release.

    • The Data link points to a set of zip files containing the contents of the release (the files are complete in themselves, and do not require files from earlier releases -- for the structure of the zip file, see Repository Organization).

    • The Spec is the version of UTS #35: LDML that corresponds to the release.

    • The Delta document points to a list of all the bug fixes and features in the release, which be used to get the precise corresponding file changes using BugDiffs.

    • The SVN Tag can be used to get the files via Repository Access.

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

For web pages with different views of CLDR data, see