Unicode Technical Standard #35

Unicode Locale Data Markup Language (LDML)
Appendix A: Modifications

For the full header, summary, and status, see Part 1: Core.

Summary

This is a partial document, describing only the changes to the LDML since the previous release. For the other parts of the LDML see the main LDML document and the links above.

Status

This is a draft document which may be updated, replaced, or superseded by other documents at any time. Publication does not imply endorsement by the Unicode Consortium. This is not a stable document; it is inappropriate to cite this document as other than a work in progress.

A Unicode Technical Standard (UTS) is an independent specification. Conformance to the Unicode Standard does not imply conformance to any UTS.

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Parts

The LDML specification is divided into the following parts:

• Part 1: Core (languages, locales, basic structure)
• Part 2: General (display names & transforms, etc.)
• Part 3: Numbers (number & currency formatting)
• Part 4: Dates (date, time, time zone formatting)
• Part 5: Collation (sorting, searching, grouping)
• Part 6: Supplemental (supplemental data)
• Part 7: Keyboards (keyboard mappings)
• Part 8: Person Names (person names)
• Part 9: MessageFormat (message format)
• Appendix A: Modifications
• Appendix B: Acknowledgments

Contents of Appendix A, Modifications

• Modifications
  • Locale Identifiers and Names
  • Misc.
  • DateTime formats
  • Numbers
  • Units of Measurement
  • Collation
  • MessageFormat
  • Keyboards
  • Modifications section
  • Acknowledgments section

Modifications

Changes in LDML Version 48 (Differences from Version 47)

Locale Identifiers and Names

• Display Name Elements Described the usage of the language element menu values core and extension, and alt="menu". Also revamped the description of how to construct names for locale IDs, for clarity.
• Special Script Codes Added the Hntl compound script. (This is also reflected in the <scriptData> elements in supplementalData.xml.)
• Likely Subtags Changed the Canonicalize step to point to the section on canonicalization.
• Unicode Locale Identifier Changed the attribute component in the EBNF to be uattribute for consistency with ufield, etc. and to reduce confusion with XML attributes.

Misc.

• Character Elements Added new exemplar types.
• DTD Annotations Added the @CDATA annotation, to indicate which elements are generated with @CDATA format
• Person Name Validation Added guidance for validating person names.

DateTime formats

• Element dateTimeFormat Added a new type relative for relative date/times, such as "tomorrow at 10:00", and updated the guidelines for using the different dateTimeFormat types.
• Using Time Zone Names Removed the "specific location format".
• timeZoneNames Elements Used for Fallback Added the gmtUnknownFormat, to indicate when the timezone is unknown.
• Metazone Names Added usesMetazone, to specify which offset is considered standard time, and which offset is considered daylight.
• Time Zone Format Terminology Added the Localized GMT format (replacing the Specific location format). This affects the behavior of the z timezone format symbol. There is also now a mechanism for finding the region code from short timezone identifier, which is used for the non-location formats (generic or specific)
• Calendar Data Specified more precisely the meaning of the era attributes in supplemental data, and how to determine the transition point in time between eras.

Numbers

• Plural rules syntax Added substantial clarifications and new examples. The order of execution is also clearly specified.
• Compact Number Formats Specified the mechanism for formatting compact numbers more precisely.
• Rule-Based Number Formatting Added a full specification. The rules have been converted to a “flat” format, which is easier for clients to handle (the old format will be retained for one more release).
• Rational Numbers Added support for formatting fractions like 5½.

Units of Measurement

• Unit Syntax Simplified the EBNF product_unit and added an additional well-formedness constraint for mixed units.
• Unit Identifier Normalization Modified the normalization process
• Mixed Units Modified the guidance for handling precision.

Collation

• Collation Added the new FractionalUCA_blanked.txt to the root collation data files.

MessageFormat

• Syntax and data model errors must now be prioritized over other errors
• The Default Bidi Strategy is now required and default
• The :offset function (previously named :math) is now available as Stable
• The :datetime, :date, and :time draft functions are updated to build on top of semantic skeletons
• :percent is added as a new draft function
• The format is renamed to "Unicode MessageFormat" for clarity
• The pattern selection definition is refactored to be easier to understand without changing its meaning

Keyboards

TBD Needs some cleanup for consistency

• A sentence was struck under the documentation of the display element. A key without output may be indicated by means of the keyId= attribute on the display, which see.
• A sentence was added under the layer element in the definition of the modifiers= attribute about hardware layouts being used as touch layouts.

Modifications section

• The Modifications section was split out to its own file, Appendix A, Modifications

Acknowledgments section

• The Acknowledgments section was split out to its own file, Appendix B, Acknowledgments

Note that small changes such as typos and link fixes are not listed above. Modifications in previous versions are listed in those respective versions. Click on Previous Version in the header until you get to the desired version.

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