CLDR 27 Release Note

No. Date Rel. Note Data Charts Spec Delta SVN Tag DTD Diffs
27.0.1 2015-03-30
v27 CLDR27.0.1 Charts27 LDML27 Δ27.0.1 release-27-0-1 NONE
27 2015-03-19 v27 CLDR27 Charts27 LDML27 Δ27 release-27 ΔDTD27


Unicode CLDR 27 has been released, providing an update to the key building blocks for software supporting the world's languages. This data is used by all major software systems for their software internationalization and localization, adapting software to the conventions of different languages for such common software tasks.

There was no Survey Tool data collection phase for CLDR 27. Instead, the release focused primarily on stability—cleaning up data inheritance and making specific fixes—as well as improvements to the JSON format of the data. Changes include the following:

  • Cleanup of region locales: A major cleanup effort was undertaken to resolve gratuitous differences between region-specific locales and the parent from which they inherit. In regional locales, it was determined where the parent value was an acceptable replacement for a child-specific value which could then be removed, providing greater consistency in behavior in the various region locales. A special effort was made to clean up country names in certain locales.
  • Changes to English inheritance: As an outcome of the cleanup effort above, the inheritance model for English locales is now simplified, making all en_XX locales inherit from either “en” directly ( for current or former U.S. territories ), or from British-influenced “en_001 - World English. This is also reflected in some changes for measurement systems. See the migration section below for a detailed description of “en_001.
  • Emoji: Data for emoji annotations and an emoji collation were added, to accompany Unicode Technical Report #51, Unicode Emoji.
  • Collation: There are new sort orders for emoji (as noted above), and an Austrian phonebook sort order. Scripts can be reordered individually, rather than only in specific groups. Fractional tertiary weights are now used that are lower than commonto allow shorter sort-keys with normal Hiragana letters. 
  • Specification: The LDML specification has descriptions of new or modified structure, plus a number of fixes and clarifications. See Modifications for a list of changes.
    • Improved documentation of locale inheritance and matching, bundle versus item lookup, and parent locale information.
    • Extensive clarifications to the intended use of the language matching data.
    • Explicit new definitions of Unicode identifiers, such as Unicode Calendar Identifier, for use in citations.
  • Charts: The navigation within charts has been improved, and new ones added:
  • JSON on github: The JSON form of the data is now available on Github, rather than being found through the above Data link.

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 KeyFor 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.

BCP47 changes

  • Added segmentation.xml, which defines a new key for controlling line break behavior per the CSS line-break property: 
    • “lb, with type values “strict, “normal, and “loose
  • Added collation (“co) type value: “emoji
  • Added timezone (“tz) type value: “pgraw (Pacific/Bougainville)

Structural additions and changes

Data additions and changes that are more likely to cause migration issues are listed in the Migration section below.

For main locale data

  • Added the top-level <annotations> element, whose <annotation> subelements provide information about characters, currently focusing on emoji. This information can be used as an input aid, for example.
  • For <contextTransform> elements, defined a new value “no-change to designate the case in which it is known that no change from the raw CLDR text (middle-of-sentence form) is needed.
  • Deprecated the standard validSublocales attribute everywhere; it allowed sublocales in a given tree to be treated as though a file for them were present when none in fact was. Now it is recommended to simply add empty “stub files to specify which sublocales are valid.
  • There is an additional temperature-generic unit, which can be used where the context makes it clear whether Celsius or Fahrenheit are being used.

For supplemental data

  • Added the <unicodeVersion> element which defines the version of the Unicode standard that is used to interpret data, particularly the data in UnicodeSets.
  • Allow multiple <dayPeriodRuleSet> elements, distinguished by a new type attribute. A <dayPeriodRuleSet> with type=“selection provides the time period data used for selecting among phrases such as “Your email arrived yesterday evening or “Your email arrived last night.
  • For the <measurementSystem> element, added a new category attribute. This is used to indicate the measurementSystem for a specific category such as temperature; this may be different than the default measurementSystem for a region.
  • For the <alias> element subelements languageAlias, scriptAlias, territoryAlias, variantAlias, and zoneAlias, the type and replacement attributes are now required.
  • Deprecated the <postalCodeData> element and its <postCodeRegex> subelement. The data was not being maintained and there are other sources of such information that are kept up to date.

    Data additions and changes

    Data additions and changes that are more likely to cause migration issues are listed in the Migration section below.

    Region sublocales, inheritance for English

    • Extensive cleanup of region sublocales (e.g. fr_CA and fr_CH, es_419 and es_MX) to eliminate gratuitous differences from parent locale data
    • Changed “en_001” to represent British-influenced “world English”; changed the inheritance for many locales that use British-influenced English to inherit directly from en_001 instead of directly or indirectly from en_GB.
    • Regularized certain spellings (like St.), spacing in currencies, interval formats (Nov 3 – 5)

    Emoji-related data

    • Added annotations data for emoji in several languages
    • Added data for a new “emoji” collation in root. Added a display name for it in English.

    Date/time symbols and formats

    • Added new standard availableFormats items for skeletons hmsv, Hmsv, hmv, Hmv
    • In several locales (ca, es, th) made more consistent distinctions between patterns using MMM vs MMMM or between patterns using E vs patterns using EEEE; where relevant, the MMMM patterns use 'de', the MMM patterns do not.
    • For Catalan, restored format wide month names with article (de març, “d’abril) as in CDLR 23; the date patterns now handle them correctly (date formats with wide month use MMMM if d is present and LLLL otherwise).
    • For Chinese-calendar date formats in root, en, zh, and zh_Hant, patterns with year now include 'r' for related Gregorian year.
    • Add supplemental data for <dayPeriodRuleSet type="selection">.


    • The CLDR 27 root collation order is still based on the UCA 7.0 DUCET, but with most of the Cyrillic contractions removed as in UCA 8.0. The Cyrillic tailorings have been updated.
    • New Austrian phonebook sort order and Emoji symbols sort order.
    • FractionalUCA.txt supports reordering of single scripts rather than groups of scripts. Implementations that support script reordering should base it on the script-first-primary boundaries and use the new reorder-reserved ranges. Some Recommended Scripts may share primary lead bytes.
    • FractionalUCA.txt tertiary weights: Some fractional root collation elements have below-common tertiary weights (e.g., 03), in particular to allow normal Hiragana letters to have common tertiary weights. This is the first time that the root collation data uses below-common tertiary weights.
    • Simpler handling of U+FFFE (merge separator); FractionalUCA.txt now uses common secondary & tertiary weights for its CE, rather than unique low ones.

    Line break variants

    • Defined a new -u- locale key for controlling line break tightness (how many break opportunities are available), and added English display names for these:
      • lb, with possible values “strict (fewer break opportunities, when long lines are okay), 
      • normal, and 
      • loose (more break opportunities, for small displays). 
    • However, the CLDR line break rules have not been updated to support the additional break variants.
      • For an example of where the rules are used, see ICU.

    Supplemental data

    • Regular updates to language/script/territory info (population, literacy, etc.) and likely subtags (which scripts / territories are defaults for languages).


    The following shows the additional coverage in this release. Because there was no major data collection this release, the difference from the previous release is very small.
    • The horizontal axis shows the number of languages. The area between lines are the additional data added in that release. 
    • The vertical axis shows the percentage of modern coverage.
    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 plateauxThe plateaux tend to “slump across versions 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 this release. 
    • The vertical axis is percent of modern coverage. Three different coverage levels are shown in the chart, modern, moderate, and basic
      • There are horizontal lines showing the moderate target% and the basic target%
      • The light lines show where data is available, but unconfirmed.
    • The horizontal axis is the number of languages in the common directory of CLDR. There are additional directories: 
      • seed for locales that have just started, and don't have enough data to be included here, and 
      • exemplar for locales that just have exemplar data (that is, the characters are used in the language).
    The definition of the various levels of coverage increases over time, as new structure and requirements are added (see Growth). 


    The version 27 Charts have been updated for the new data. Navigation has been improved, and some new charts have been added.

    Specification changes

    The specification changes are detailed in LDML Modifications. Other than documentation of the new structure, enhancements include:
    • Improved documentation of locale inheritance and matching, bundle versus item lookup, and parent locale information.
    • Extensive clarifications to the intended use of the language matching data.
    • For transform rules, documented the use of $ in contexts to mean “off the end of the string”
    • For number systems, document that “latn” is always an acceptable numbering system
    • Clarify usage of doubled or tripled ¤ (U+00A4) in currency patterns.
    • Clarify the construction of long (displayName) formats using the plural rules. 

    Changes to JSON structure and data

    All JSON data has been regenerated to correspond to the XML as published in the 27 release. Note: Per CLDR committee decision, all JSON data is now generated to include only those data fields that are marked “draft='contributed' or higher. Unconfirmed or provisional data will not be included in the resulting JSON. This is the same threshhold that is used by the ICU Project for consuming CLDR's data.

    Beginning with the CLDR 27 release, the CLDR committee is pleased to announce a restructuring of the published JSON data, in an attempt to make it more consumable to the JavaScript development community. The JSON data has been organized into installable packages, that can be installed using bower. In addition, the JSON data packages are available via Github. To access the CLDR JSON data, please view our Github repository at

    Survey Tool

    No significant changes.


    The main “pain points for migration have typically been changes in:
    • plural/ordinal 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 Inheritance

    • Changed “en_001” to represent British-influenced “World English”. English sublocales whose territory has a strong historical relationship with the U.S., or is a territory of the U.S. will continue to inherit the bulk of their locale data directly from “en” (U.S. English). Otherwise, the locale will inherit the bulk of its data from “en_001 - World English”. Locale “en_001 - World English” has the following general characteristics:
      • British influenced spellings for units (i.e. “metre instead of “meter ).
      • Celsius as the default temperature scale.
      • European-style date ordering (18 March instead of “March 18)
      • 12 hour clock
      • No specifically recognized short timezone abbreviations.

      Changes to Collation

      • Cyrillic contractions moved from root to tailorings.
      • This is the first time that the FractionalUCA.txt root collation data uses below-common tertiary weights.
      • The FractionalUCA.txt collation element for U+FFFE (merge separator) now uses common secondary & tertiary weights, rather than unique low ones.
      • Implementations which support script reordering should be modified to reorder single scripts, not groups of scripts.

      Changes to Day Period types

      • The dayPeriodRule type values (other than am, pm, noon, midnight) have changed to a more generally useful set (there is not a 1-1 matchup):
        • from: earlyMorning, morning, lateMorning, midDay, afternoon, evening, lateEvening, night, weeHours
        • to: morning1, morning2, afternoon1, afternoon2, evening1, evening2, night1, night2

      Changes to measurementSystem

      • The default measurement system for the UK has been changed from "metric" to "UK" (Imperial). The situation in the UK is quite complex: see Metrication in the United Kingdom. Imperial units are used for many commonplace measures, while for others metric units are the norm. If their primary focus is on the latter, implementations have fewer problems if they revert the value to "metric". Note: the choice of which unit is used in which domain is complex: even with the metric system, in one country a person’s height may be expressed as 188cm, while in another as 1.88m. CLDR is moving toward support of such context with the new category attribute, but more research is needed.

      Changes to Language Matching

      • There are a number of language rules that are used for last-resort fallbacks, such as Abkhazian→Russian. These were previously given inverted values (10 instead of 90), which caused them to be — in effect — inoperative. The values are now fixed, which means that they will now cause matches that didn't formerly occur.
      • Language matching among regions has been changed for the new inheritance structure in English, which will change some matches.

      Changes to Plurals/Ordinals

      • Assamese ordinal types are changed to be the same as Bengali. This should not cause migration problems, since the set of categories is identical.

      Changes in Date/Time/Number formatting

      • For Catalan, restored format wide month names with article ("de març, "d’abril) as in CDLR 23; the date patterns now handle them correctly (date formats with wide month use MMMM if d is present and LLLL otherwise).
      • For Chinese-calendar date formats in root, en, zh, and zh_Hant, patterns with year now include 'r' for related Gregorian year.

      Other Data changes

      • The cleanup of regional locales caused some general changes
        • Regularized certain spellings (like St.), spacing in currencies, interval formats (Nov 3 – 5)
        • General changes to the name for British Pound
        • Spacing changes in Chinese units
        • More consistent use of en-dash (intervals, also date ranges such as in Japanese era names in Swedish)
      • There were a large number of casing changes for Russian (scripts lowercased), Portuguese
      • Locale swc (Congo Swahili) has now been merged into locale sw_CD (Swahili; Congo - Kinshasa). See CLDR Ticket #8079 for a detailed discussion on the rationale.
      • In English (en = en-US), the units/short plural forms for duration-hour/minute/second are changed to “hr, “min, and “sec; en_001 overrides this to keep using “hrsmins, and “secs.
      • Misc. other changes, such as some Korean territory names.
      • Some metazone periods

      Known issues

      • In Afrikaans data, there is inconsistent use of periods for Gregorian format & stand-alone abbreviated month names [#8240].
      • In English (en), the narrow symbol for "volume-liter" inconsistently uses "l", through "L" is used elsewhere in "en" [#8296].

      CLDR 27.0.1 Maintenance Release

      Unicode CLDR 27.0.1 is a very small maintenance release that is intended to fix some specific problems that were found shortly after CLDR 27 was published. If you have already downloaded version 27 and are not impacted by any of the specific issues mentioned below, then there is no specific need to upgrade from 27 to 27.0.1.  All data in common/main is identical between version 27 and version 27.0.1.

      The following specific problems are addressed in CLDR 27.0.1

      • Problems with language matching: A significant problem was found in the way language matching data was being converted to ICU, which required an update to common/supplemental/languageInfo.xml, as well as the tooling used to convert data from CLDR to ICU.  See [#8297]
      • JSON Installation Problems:
        • When installing via NPM, need to use peerDependencies instead of dependencies, so that dependent packages will align at the same directory level as the installed package.  See [#8301]
        • The approved JSON packaging document stated that the cldr-core package would contain "defaultContent.json", which would list the locale identifiers that were omitted from the JSON packaging because they were identical to the parent. This file was inadvertently omitted from the v27 distribution. See [#8302]

      CLDR 27.0.3 Maintenance Release (Github tag only)

      The approved JSON packaging document stated that the cldr-core package would contain "defaultContent.json", which would list the locale identifiers that were omitted from the JSON packaging because they were identical to the parent. This file should have been pushed to Github in the 27.0.1 Maintenance Release but was not.  The file has been pushed to Github and all packages have been tagged as 27.0.3.  The only difference between 27.0.1 and 27.0.3 is the addition of defaultContent.json.


      • 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.
      • For more details see CLDR Releases (Downloads).

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

      For web pages with different views of CLDR data, see