UNICODE CHARACTER DATABASE

Summary

This document describes the format and content of the Unicode Character Database (UCD)

Status

This file and the files described herein are part of the Unicode Character Database and are governed by the terms of use at http://www.unicode.org/terms_of_use.html.

The References provide related information that is useful in understanding this document.

Warning: the information in this file does not completely describe the use and interpretation of Unicode character properties and behavior. It must be used in conjunction with the data in the other files in the Unicode Character Database, and relies on the notation and definitions supplied in The Unicode Standard. All chapter references are to Version 5.0.0 of the standard unless otherwise indicated.

Contents

• Introduction
• Conformance
• UCD File Format
• UCD Property Files
• Auxiliary Property Files
• Derived Extracted Property Files
• Other UCD Files
• Properties
• Property and Property Value Matching
• Property Invariants
• Property Values
  • General Category Values
  • Bidi Class Values
  • Character Decomposition Mapping
  • Canonical Combining Classes
  • Decompositions and Normalization
  • Case Mappings
  • Unihan Tags
• References
• Modification History
• UCD Terms of Use

Introduction

The Unicode Character Database (UCD) is a set of files that define the Unicode character properties and internal mappings. This document describes the properties and files that are part of The Unicode Standard, Version 5.0 [U5.0]. For a description of the changes in this version, see Modification History.

The file structure for the UCD changed in Version 4.1.0. From that point on, the successive versions of the UCD are complete versions, so that so that users of the standard do not need to assemble the correct version of each file from different update directories for previous versions in order to have a complete set of files for a version. Each version is in a directory of the following form:

http://www.unicode.org/Public/5.0.0/ucd/

Within this directory the structure is the same as in versions prior to 4.1.0, with two changes:

• The file names are unversioned in the final release (although they may be versioned during beta review of the UCD data). This allows people using the files to not worry about removing the release versions from the individual files, and allows the html files in the release to link to specific files.
• An auxiliary directory has been added. In Version 5.0.0 it contains properties associated with UAX #29: Text Boundaries [Breaks].

Conformance

For information on the meaning and application of the terms normative, informative, and provisional, see Section 3.5, "Properties" in the Unicode Standard, Version 5.0.

UCD File Format

Files in the UCD use the following format, unless otherwise specified.

• Each line of data consists of fields separated by semicolons. The fields are numbered starting with zero. Code points are expressed as hexadecimal numbers with four to six digits. They are written without "U+". Within a sequence of code points, spaces are used for separation. Leading and trailing spaces within a field are not significant.

• The first field (0) of each line in the Unicode Character Database files represents a code point or range. The remaining fields (1..n) are properties associated with that code point.

• A range of code points is specified by the form "X..Y". Each code point from X to Y has the associated property value. For example (from Blocks.txt):

  0000..007F; Basic Latin
  0080..00FF; Latin-1 Supplement

• Property values may be omitted if they have a "default" value. For string properties, the default value is the character itself. For others, the default value is listed in a comment. For example (from Scripts.txt):

  #  All code points not explicitly listed for Script
  #  have the value Common (Zyyy).

• Where a file contains values for multiple properties, the second field will contain the name of the property and the third field will contain the property value. For example (from DerivedNormalizationProps.txt):

  03D2  ; FC_NFKC; 03C5           # L&  GREEK UPSILON WITH HOOK SYMBOL
  03D3  ; FC_NFKC; 03CD           # L&  GREEK UPSILON WITH ACUTE AND HOOK SYMBOL
  

• For binary properties, the second field given is the name of the applicable property, with the implied value of the property being "True". Only the ranges of characters with the binary property value of True are listed. For example (from PropList.txt):

  1680       ; White_Space # Zs      OGHAM SPACE MARK
  180E       ; White_Space # Zs      MONGOLIAN VOWEL SEPARATOR
  2000..200A ; White_Space # Zs [11] EN QUAD..HAIR SPACE

• For backwards compatibility, in the file UnicodeData.txt a range is specified not by the form "X..Y", but by their start and end characters. In such cases, the names of characters in the range are algorithmically derivable. Surrogate code points and private use characters have no names. See [U5.0] for more information.
• Hash marks ("#") are used to indicate comments: all characters from the hash mark to the end of the line are comments, and disregarded when parsing data. In many files, the comments on data lines use a common format.

  00BC..00BE ; numeric # No [3] VULGAR FRACTION ONE QUARTER..VULGAR FRACTION THREE QUARTERS

• The first part of the comment is generally the UCD general category. The symbol "L&" indicates characters of type Lu, Ll, or Lt. This is the same as the LC property in PropertyValueAliases. The code point ranges are calculated so that they all have the same General Category (or LC). While this results in more ranges than are strictly necessary, it makes the contents of the ranges clearer. The second part of the comment (in square brackets), indicates the number of items in a range, if there is one. The third part is the name of the character in field zero: if it is a range, then the character names for the ends of the range are separated by "..".
  • However, the comments are purely informational, and may change format or be omitted in the future. They should not be parsed for content.
• In the QuickCheck property table, NF* refers to one of NFD, NFC, NFKC, or NFKD.
• The Unihan data format differs from the standard format, and is described in Unihan.html. That file also describes which properties are informative, which are normative, and which are provisional.
• In some cases, segments of a data file are distinguished by a line starting with an "@" sign.
• The files use UTF-8, with the exception of NamesList.txt, which is encoded in Latin-1. Unless otherwise noted, non-ASCII characters only appear in comments.

UCD Property Files

The following table describes the format and meaning of each property data file in the main directory of the UCD. (An index by property name, rather than file, is found at Properties.) The first column lists the files and the properties for which they contain data. The second column indicates the type of the property: String, Numeric, Enumeration (non-binary), Binary, Catalog, or Miscellaneous. Catalog properties have enumerated values which are expected to be regularly extended with successive versions of the Unicode Standard. This distinguishes them from Enumeration properties, whose enumerated values constitute a logical partition space, for which new values will generally not be added in successive versions of the standard. An example of a Catalog property is the Block property. Miscellaneous properties do not fit into the other property categories, and currently include character names, comments about characters, or the Unicode_Radical_Stroke property (a combination of numeric values). The third column indicates the status (Normative, Informative, or Provisional), and the fourth column provides a description of the data.

The files with a small number of properties are listed first, followed by the files with a large number of properties: DerivedCoreProperties.txt, DerivedNormalizationProps.txt, Proplist.txt, and UnicodeData.txt. For UnicodeData, the field numbers are supplied in the description. In a number of cases, fields in a data file only contribute to a UCD property; for example, the name field in UnicodeData.txt does not provide all the values for the Name property; Jamo.txt must be used as well.

None of these properties should be used without consulting the relevant discussions in the Unicode Standard.

Where a data file does not explicitly list property values for all code points, the code points are given default property values. These default property values are documented in the data files, with the exception of UnicodeData.txt. For that case the default property values are listed below in parentheses after the property name, with (=) indicating the code point itself.  The default property values are also documented in any corresponding extracted data file.

b = NFKC(Fold(a));
c = NFKC(Fold(b));
if (c != b) add mapping from a to c

Note:

Stabilized properties are no longer actively maintained, nor are they extended as new characters are added.

Auxiliary Property Files

A number of auxiliary properties are contained in files in the auxiliary subdirectory. They consist of the following:

Derived Extracted Property Files

The following properties of the UCD have been separated out, reformatted, and listed in range format, one property per file, except as noted. These files are provided purely as a reformatting of existing data, any exceptions are noted in the table below. All files for derived extracted properties are contained in a subdirectory called extracted.

Bidi Note: The BidiMirrored property and the BidiMirroring property are different. The former is a normative property that indicates whether characters are mirrored in a right-to-left context in the Unicode Bidirectional Algorithm. The latter is an informative mapping of a subset of the BidiMirrored characters, to characters that normally have the corresponding mirrored glyph.

Other UCD Files

The following files in the Unicode Character Database are not used directly for Unicode properties.  For more information about these files, see the referenced technical report(s), files, or section of Unicode Standard.

Properties

The following table lists the properties in the UCD. They are roughly organized into groups based on the usage of the property (this grouping is purely for convenience, and has no other implications). The link on each property leads to description in the file index. The contributory properties (those of the form Other_XXX) are sets of exceptions used to generate properties in DerivedCoreProperties.txt. They are incomplete by themselves and not intended for independent use, for example an API returning property values would implement the corresponding derived core property instead.

Property and Property Value Matching

Properties and property values may have multiple aliases, such as abbreviated names and longer, more descriptive names. For example, one can write either Line_Break or LB for the Line Break property, and either OP or Open_Punctuation for one of its values. When matching property names and values, it is strongly recommended that all aliases in the UCD be recognized, and that loose matching should be applied to all property names and property values according to the following:

Numeric Properties

For all numeric properties, and properties such as Unicode_Radical_Stroke that are combinations of numeric values, use the following loose matching rule:

LM1. Apply numeric equivalences

• "01.00" is equivalent to "1".
• "1.666667" in the UCD is a repeating fraction, and equivalent to 10/6.

Character Names

LM2. Ignore case, whitespace, underscore ('_'), and all medial hyphens except the hyphen in U+1180.

• "zero-width space" is equivalent to "zero width space" or "zerowidthspace"
• "character -a" is not equivalent to "character a"

Others

For all property names, property value names, and for property values for Enumerated, Binary, or Catalog properties, use the following loose matching rule:

LM3. Ignore case, whitespace, underscore ('_'), and hyphens.

• "linebreak" is equivalent to "Line_Break" or "Line-break"

Otherwise loose matching should not be done for the property values of String properties, as case distinctions or other distinctions in those values may be significant.

Property Invariants

Values in the UCD are subject to correction as errors are found; however, some characteristics of the properties and files are considered invariants. Applications may wish to take these invariants into account when choosing how to implement character properties. All formally guaranteed invariants of property values are described in Unicode Policies. The following lists some additional invariants regarding file organization and more detail on a few of the invariants in the Unicode Policies.

UnicodeData Fields

• The number of fields in UnicodeData.txt is fixed.
  • Any additional information about character properties to be added in the future will appear in separate data files, rather than being added as an additional field or by subdivision or reinterpretation of existing fields.
• The order of the fields is also fixed.

Combining Classes

• The values of the Canonical_Combining_Class property are invariant.
• Combining classes are limited to the values 0 to 255.
  • In practice, there are far fewer than 256 values used; Unicode 3.0 used 53 values, and Unicode 4.0 used 54 values total. (For details, see DerivedCombiningClasses.txt in the UCD.) Implementations may take advantage of this fact for compression, since only the ordering of the non-zero values matters for the Canonical Ordering Algorithm. In principle, it would be possible for up to 256 values to be used in the future; however, new combining classes are added very seldom. There are implementation advantages in restricting the number of classes to 128—for example, the ability to used signed bytes without widening to ints in Java.
• All characters other than those of General Category M* have the combining class 0.
  • Currently, the obverse is also true: all characters other than those of General Category Mn have the value 0. However, some characters of General Category Me or Mc may be given non-zero values in the future.

Decimal Digits

• In Unicode 4.0 and thereafter, the General_Category value Decimal_Number (Nd), and the Numeric_Type value Decimal (de) are defined to be co-extensive, that is, the set of character having Nd will always be the same as the set of characters having de.

Property Values

The following gives a summary of property values for certain properties. Other property values are documented in other locations; for example, the line breaking property values are documented in UAX #14: Line Breaking Properties [Line].

General Category Values

The values in this field are abbreviations for the following values. For more information, see the Unicode Standard.

Note: The Unicode Standard does not assign information to control characters (except for certain cases). Implementations will generally also assign categories to certain control characters, notably CR and LF, according to platform conventions. See Section 5.8 "Newline Guidelines" for more information.

Note: The term "L&" is used to stand for Uppercase, Lowercase or Titlecase letters (Lu, Ll, or Lt) in comments. The LC value in PropertyValueAliases.txt also stands for Uppercase, Lowercase or Titlecase letters.

Bidi Class Values

Please refer to UAX #9: The Bidirectional Algorithm [BIDI] for an explanation of the algorithm for Bidirectional Behavior and an explanation of the significance of these categories.

Character Decomposition Mapping

The tags supplied with certain decomposition mappings generally indicate formatting information. Where no such tag is given, the mapping is canonical. Conversely, the presence of a formatting tag also indicates that the mapping is a compatibility mapping and not a canonical mapping. In the absence of other formatting information in a compatibility mapping, the tag is used to distinguish it from canonical mappings.

In some instances a canonical mapping or a compatibility mapping may consist of a single character. For a canonical mapping, this indicates that the character is a canonical equivalent of another single character. For a compatibility mapping, this indicates that the character is a compatibility equivalent of another single character. The compatibility formatting tags used are:

Reminder: There is a difference between decomposition and decomposition mapping. The decomposition mappings are defined in the UnicodeData, while the decomposition (also termed "full decomposition") is defined in Chapter 3 to use those mappings recursively.

• The canonical decomposition is formed by recursively applying the canonical mappings, then applying the canonical reordering algorithm.
• The compatibility decomposition is formed by recursively applying the canonical and compatibility mappings, then applying the canonical reordering algorithm.

Canonical Combining Class Values

Note: some of the combining classes in this list do not currently have members but are specified here for completeness.

Decompositions and Normalization

Decomposition is specified in Chapter 3. UAX #15: Unicode Normalization Forms [Norm] specifies the interaction between decomposition and normalization. That report specifies how the decompositions defined in UnicodeData.txt are used to derive normalized forms of Unicode text.

Note that as of the 2.1.9 update of the Unicode Character Database, the decompositions in the UnicodeData.txt file can be used to recursively derive the full decomposition in canonical order, without the need to separately apply canonical reordering. However, canonical reordering of combining character sequences must still be applied in decomposition when normalizing source text which contains any combining marks.

The QuickCheck property values are as follows:

For more information, see Section 14 in UAX #15: Unicode Normalization Forms [Norm].

Case Mappings

There are a number of complications to case mappings that occur once the repertoire of characters is expanded beyond ASCII. For more information, see Chapter 3 in Unicode 5.0.

For compatibility with existing parsers, UnicodeData.txt only contains case mappings for characters where they are one-to-one mappings; it also omits information about context-sensitive case mappings. Information about these special cases can be found in a separate data file, SpecialCasing.txt.

Unihan Tags

A large number of properties specific to Han ideographs are contained in the Unihan Database, where they are called Unihan tags. The Unihan.txt file is described in Unihan.html.

References

Modification History

This section provides a summary of the changes between update versions of the Unicode Standard. The modifications prior to Unicode 4.0 only listed changes in UnicodeData.txt. From 4.0 onward, the consolidated modifications include the changes in other files.

Unicode 5.0.0

This document:

• Added new properties.
• Updated property invariants for combining classes.
• Reorganized order of sections in the document for clarity.

Common file changes:

In many data files an explicit default property assignment range was added (in a machine-readable comment line), to assist implementations in assigning values for code points not otherwise listed in the data file.

Changes in specific files:

In some of the following entries, references are made to a Public Review Issue (PRI). See http://www.unicode.org/review/resolved-pri.html for more information about those cases.

Appropriate data files were updated to include the 1369 new characters added in Unicode 5.0.

Two new data files, NameAliases.txt and NamedSequencesProv.txt, were added to the UCD.

• UnicodeData.txt

  Note that except for the changes involving U+0294 LATIN LETTER GLOTTAL STOP, changes made to General_Category and Bidirectional_Class impacted primarily a handful of archaic letters.

  • U+10341 GOTHIC LETTER NINETY was changed from gc=Lo to gc=Nl. This change also impacted a numeric field, for consistency.
  • U+103D0 OLD PERSIAN WORD DIVIDER was changed from gc=So to gc=Po, and from bc=ON to bc=L.
  • U+103D1..U+103D5 were changed from bc=ON to bc=L.
  • U+23B4..U+23B6 were changed from various punctuation assignments to gc=So.
  • U+2132 TURNED CAPITAL F was changed from gc=So to gc=Lu, and from bc=ON to bc=L.
  • U+2183 ROMAN NUMERAL REVERSED ONE HUNDRED was changed from gc=Nl to gc=Lu.
  • U+0294 LATIN LETTER GLOTTAL STOP was changed from gc=Ll to gc=Lo.
  • Casing assignments were added for several characters for new case pairs.
  • Case mappings were removed for U+0294 LATIN LETTER GLOTTAL STOP and updated for U+0241 LATIN CAPITAL LETTER GLOTTAL STOP.
  • 30 characters were changed to Bidi_Mirrored=Y. These consisted of compatibility paired punctuation and some quotation marks. See PRI #80 and PRI #91.
• Unihan.txt
  • 4 new provisional properties were added, and extensive corrections and additions to other properties were made. See Unihan.html for the modification history.
• ArabicShaping.txt
  • New joining classes were added for N'Ko.
• BidiMirroring.txt
  • 30 entries were added, to give glyph mappings for characters changed to Bidi_Mirrored=Y. See PRI #80 and PRI #91.
• Blocks.txt
  • Added 9 new block definitions.
• DerivedCoreProperties.txt
  • The deprecated derived property, Grapheme_Link, was added to this file.
• LineBreak.txt
  • There were numerous updates to linebreaking properties. See the Modification History in UAX #14 for details. Also see PRI #88.
• NamedSequences.txt
  • 6 named sequences for Gurmukhi and one for Latin were removed.
• PropertyValueAliases.txt
  • Appropriate aliases were added for new Block and Script values.
• PropList.txt
  • The Grapheme_Link property was deprecated and moved to DerivedCoreProperties.txt as derivable. U+034F COMBINING GRAPHEME JOINER was removed from the derivation.
  • U+1D6A4 MATHEMATICAL ITALIC SMALL DOTLESS I and U+1D6A5 MATHEMATICAL ITALIC SMALL DOTLESS J were added to Other_Math.
  • U+1039F UGARITIC WORD DIVIDER and U+103D0 OLD PERSIAN WORD DIVIDER were added to Terminal_Punctuation.
• Scripts.txt
  • 5 new Script values were added: Balinese, Cuneiform, Phoenician, Phags-pa, and Nko.
  • A new Script value Unknown was added and made the default for unassigned characters. See PRI #87.
  • 3 Mongolian punctuation characters used by Phags-pa were changed to Script=Common.
  • U+1DBF MODIFIER LETTER SMALL THETA was changed from Script=Latin to Script=Greek.
  • U+2132 TURNED CAPITAL F was changed from Script=Common to Script=Latin.
• StandardizedVariants.txt
  • 6 standardized variation sequences were added for Phags-pa.
• WordBreakProperty.txt
• U+2132 TURNED CAPITAL F was added to ALetter.
• 220 characters from the Myanmar, Khmer, Tai Le, and New Tai Lue scripts were removed from ALetter, because those scripts do not cusomarily use spaces between words and require special handling.

Unicode 4.1.0

This document:

• Added description of new directory and release structure, including the Auxiliary files.
• Removed exception for field numbering in LineBreak and EastAsianWidth.
• Added new properties, and changed some of the documentation of the identifier properties.
• Removed the material that is now to be in Unihan.html
• Removed the listing of default BIDI properties, referring now to  extracted/DerivedBidiClass.txt
• Replaced direct links to UAXes with links to references section.

Common file changes:

All remaining files not corrected for Unicode 4.0.1 have had their headers updated to explicitly point to Terms of Use. The headers have also been synchronized somewhat to share a more common format for file version, date, and pointers to documentation. The major exception is UnicodeData.txt, which for legacy reasons, has no header.

Changes in specific files:

In some of the following, reference is made to a Public Review Issue (PRI). See http://www.unicode.org/review/resolved-pri.html for more information about those cases.

Appropriate data files were updated to include the 1273 new characters added in Unicode 4.1.

The description of the Unihan properties was separated out from UCD.html, and extensively revised, and now appears in Unihan.html.

An auxiliary directory has been added. In 4.1.0 it contains properties associated with UAX #29: Text Boundaries [Breaks].

• UnicodeData.txt
  • The Bidi_Class of U+202F was changed from bc=WS to bc=CS. See PRI #45.
  • The Bidi_Class of U+FF0F was changed from bc=ES to bc=CS. See PRI #44.
  • The Bidi_Class of U+2212 MINUS SIGN and 9 other characters similar to either a minus sign or a plus sign were changed to bc=ES. See PRI #57.
  • U+30FB KATAKANA MIDDLE DOT and U+FF65 HALFWIDTH KATAKANA MIDDLE DOT were changed from gc=Pc to gc=Po. See PRI #55.
  • Case mappings were added for Georgian capitals (Asomtavruli) to map them to the newly added Nuskhuri alphabet.
  • U+A015 YI SYLLABLE WU was changed from gc=Lo to gc=Lm.
  • 9 Ethiopic digits were changed from gc=Nd to gc=No.
  • The Numeric_Type of U+1034A GOTHIC LETTER NINE HUNDRED was changed from nt=None to nt=Nu, and it was given a Numeric_Value of 900.
  • Uppercase and titlecase mappings were added for U+019A LATIN SMALL LETTER L WITH BAR and U+0294 LATIN LETTER GLOTTAL STOP to map them to newly added capital letters.
• Unihan.txt
  • Extensive additions and corrections were made for this data file. See Unihan.html for the modification history.
• ArabicShaping.txt
  • The Joining_Group of U+06C2 ARABIC LETTER HEH GOAL WITH HAMZA ABOVE was changed to jg=Heh_Goal.
• BidiMirroring.txt
  • The Bidi_Mirroring_Glyph value for U+2A2D was corrected.
• Blocks.txt
  • Added 20 new block definitions.
• LineBreak.txt
  • The Line_Break property of all conjoining jamos was updated from lb=ID to make use of Hangul-specific Line_Break property values, aligned with the Hangul_Syllable_Type property.
  • Many other corrections were made to the Line_Break property of characters, particularly for punctuation marks specific to Runic, Mongolian, Tibetan and various Indic scripts. For details on these changes, see UAX #14.
• PropertyAliases.txt
  • Properties and aliases were added for UAX #29, Text Boundaries: Grapheme_Cluster_Break, Word_Break, and Sentence_Break.
  • Properties and aliases were added for: Other_ID_Continue, Pattern_White_Space, and Pattern_Syntax.
  • An alias was added for White_Space: "space", for compatibility with POSIX.
• PropertyValueAliases.txt
  • Property value aliases were added for all new properties, and for new values added to existing catalog properties (blocks and scripts).
  • Property value aliases were added for compatibility with POSIX: "cntrl", "digit", and "punct"
• PropList.txt
  • 3 new properties were added: Other_ID_Continue, Pattern_White_Space, and Pattern_Syntax.
  • U+30A0 KATAKANA-HIRAGANA DOUBLE HYPHEN was given the Dash property.
  • U+A015 YI SYLLABLE WU was given the Extender property.
  • Golden number runes (U+16EE..U+16F0), Roman numerals (U+2160..U+2183), and U+1034A GOTHIC LETTER NINE HUNDRED were removed from Other_Alphabetic.
  • Circled Latin letters (U+24B6..U+24E9) were added to Other_Alphabetic. These changes to Other_Alphabetic were to better align Alphabetic and casing properties. The derived property Alphabetic is now a superset of the derived properties Lowercase and Uppercase, for compatibility with POSIX-style character classes.
  • 3 musical symbol combining flags (U+1D170..U+1D172) were added to Other_Grapheme_Extend to fix an inconsistency in the data.
  • U+200B ZERO WIDTH SPACE was removed from Other_Default_Ignorable_Code_Point.
• Scripts.txt
  • 8 new Script values were added: Buginese, Coptic, New_Tai_Lue, Glagolitic, Tifinagh, Syloti_Nagri, Old_Persian, and Kharoshthi.
  • The Script value Katakana_Or_Hiragana (Hrkt) was removed.
  • The Script for the 14 Coptic letters in the Greek and Coptic block were updated to sc=Copt.
  • 10 characters (punctuation and extenders) shared by Katakana and Hiragana were changed from sc=Hrkt to sc=Zyyy.
• SpecialCasing.txt
  • The case mapping contexts defined in this file were updated.
  • A number of clarifying changes were made to comments in the header of this data file.

Unicode 4.0.1

This document:

• Added two new properties
• Added the property types Catalog and Miscellaneous
• Described loose matching of property names and values
• Added to file format

Common file changes:

Some property values have different casing (upper vs. lower) for consistency between the data files and the PropertyValueAlias file. There are some additional changes in comments:

• Nearly all files changed headers to explicitly point to Terms of Use
• Names for code points without names now have a more uniform style, such as <reserved-1234>
• Where characters with a default value are not listed, that information is indicated in the total code point counts
• The full property name and property value name (for enumerated properties) is usually supplied in a comment

Changes in specific files:

In some of the following, reference is made to a Public Review Issue (PRI). See http://www.unicode.org/review/resolved-pri.html for more information about those cases.

• UnicodeData.txt
  
  • Changed general category of Zero Width Space (U+200B) from Zs to Cf. For background information, see PRI #21.
  • Bidi Conformance was made much clearer and more rigorous, also resulting in a number of property changes:
    
    • Several Bidi fixes impact number and date formatting with the following characters: +, -, /
    • Braille symbols were changed to being strong Left-to-right, to reflect usage.
    • A review of BN and Default Ignorable code points resulted in a number of changes: for details, see PRI #28.
    • Some other bidi tweaks were made for consistency.
  • While the properties of the Join_Controls have not changed, their role in combining characters sequences has. For more information, see http://www.unicode.org/versions/Unicode4.0.1/.
  • Removed an extraneous space at the end of the name field for two characters.
• Unihan.txt
  • A major update of the Unihan data file, to bring it up-to-date for Unicode 4.0. (It was not released in Version 4.0.0, because of the time required to complete and check corrections to the data file.) This update rolls in fixes for nearly all known errors in the prior version of the file and adds a very large amount of other informative data. For details, see the header of that file.
  • Added three new tags: kHanyuPinlu,  kGSR, and kIRG_USource.
  • Completed data for kCihaiT, kCowles, kGradeLevel, and kLau
  • The kMandarin field has been corrected and its order restored to a "frequency" order
• ArabicShaping.txt
  • Moved one entry into code point order.
• Blocks.txt
  • Corrected name of the Cyrillic Supplement block.
• DerivedCoreProperties.txt
  • ZWNJ/ZWJ (U+200C..U+200D) now have the Grapheme_Extend property.
• DerivedNormalizationProps.txt
  • While not actually changing the particular values associated with the Quick Check properties for characters, a revision was made in how the Quick Check properties are expressed in the file, to bring it more into line with the model for other properties. This resulted in a significant change in the format of the data file and the explicit separation of Yes, No, and Maybe values. In addition, the actual aliases for the property changed in the data file.
• Index.txt
  • Updated to correspond to the character index published as part of the Unicode Standard, Version 4.0.
• LineBreak.txt
  • Many changes for consistency and to better match best practice in existing line break implementations; for details, see UAX #14: Line Breaking Properties
• PropertyAliases.txt
  • Addition of some property categories, with the order of property aliases adjusted for clarity.
  • Addition of alias entries for the new STerm and Variation_Selector properties.
• PropertyValueAliases.txt
  • Addition of specific values and aliases for age.
  • Addition of second alias for the Cyrillic Supplement block.
  • Addition of second alias for the Inseparable value of the Line Break property.
  • Revision of the all the Normalization Quick Check properties, to replace the pseudo-property "qc" with actual specific properties with explicit enumerated value aliases.
  • Addition of Katakana_Or_Hiragana script alias.
  • Fixed None (so it is used uniformly in first aliases instead of being the only n/a)
• PropList.txt
  • Major revision of the Other_Math property to align the derived Math property with the explanation given in UTR #25.
  • Extension of the list of characters with the Soft_Dotted property.
  • Significant update of the list of characters with the Terminal_Punctuation property.
  • Addition of a new STerm property, to simplify the description used in UAX #29.
  • Addition of the Variation_Selector property.
  • Reassignment of the list of characters with the Other_Default_Ignorable_Code_Point property, to enable simpler derivation.
  • Addition of ZWNJ/ZWJ (200C..200D) to Other_Grapheme_Extend.
• Scripts.txt
  • Significant revision of script assignments, to assign specific script values to many characters that previously had the Common script value.
  • Addition of the Katakana_Or_Hiragana script value, with list of characters for it.
  • The Common values are now listed, for comparison.
• SpecialCasing.txt
  • Correction of typo in comments.

Unicode 4.0

• UnicodeData.txt
  • Decimal Digits
    • Numeric_Type=decimal digit now aligned with General_Category=Nd
  • Modifier letters*
    • The general category of 02B9..02BA, 02C6..02CF changed to general category Lm.
• Other Files
  • New Properties and Values
    • Hangul_Syllable_Type, Unicode_Radical_Stroke
    • CJK numeric values added.
    • PropertyValueAliases adds block names
    • UCD fallback props more precisely defined, for code points not explicitly in data files
    • Added script value for Braille
    • New line breaking properties: NL, WJ
  • Khmer
    • Two Khmer characters are deprecated; four others strongly discouraged.
  • Special Casing
    • Fixed for Turkish, Lithuanian
  • Default Ignorables
    • Hangul Filler characters
    • Soft-Hyphen, CGJ, ZWS
    • Arabic End of Ayah and Syriac Abbreviation Mark no longer DI (their shaping classes are also fixed.)
  • Grapheme_Extend
    • Removes halfwidth katakana marks, most Mc (except as needed for canonical equivalence)
  • Stabilized Properties
    • The Hyphen property is now stabilized.

Unicode 3.2

Modifications made for Version 3.2.0 of UnicodeData.txt include:

• Addition of 1016 new entries, to cover new characters encoded in Unicode 3.2.
• Updated ISO 6429 names for control functions to match the currently published version of that standard.
• Changed general category for Mongolian free variation selectors (U+180B..U+180D) from Cf to Mn.
• Changed general category for U+0B83 TAMIL SIGN VISARGA (aytham) from Mc to Lo.
• Changed general category for U+06DD ARABIC END OF AYAH from Me to Cf.
• Changed general category for U+17D7 KHMER SIGN LEK TOO from Po to Lm.
• Changed general category for U+17DC KHMER SIGN AVAKRAHASANYA from Po to Lo.
• Changed canonical decomposition for U+F951 from 96FB to 964B (see Corrigendum #3: U+F951 Normalization).

Unicode 3.1.1

Modifications made for Version 3.1.1 of UnicodeData.txt include:

• Modification of ISO 10646 annotation regarding Greek tonos, affecting entries for U+0301 and U+030D.

Unicode 3.1

Modifications made for Version 3.1.0 of UnicodeData.txt include:

• Addition of 2237 new entries, to cover new characters and new ranges of unified Han characters encoded in Unicode 3.1.
• Changed General Category value of 16EE..16F0 (Runic golden numbers) from No to Nl.

Unicode 3.0.1

Modifications made for Version 3.0.1 of UnicodeData.txt include:

• Added 5- and 6-digit representation of code points past U+FFFF.
• Added Private Use range definitions for Planes 15 and 16.
• Minor additions for the 10646 comment field.

Unicode 3.0.0

Modifications made for Version 3.0.0 of UnicodeData.txt include many new characters and a number of property changes. These are summarized in Appendix D of The Unicode Standard, Version 3.0.

Unicode 2.1.9

Modifications made for Version 2.1.9 of UnicodeData.txt include:

• Corrected combining class for U+05AE HEBREW ACCENT ZINOR.
• Corrected combining class for U+20E1 COMBINING LEFT RIGHT ARROW ABOVE
• Corrected combining class for U+0F35 and U+0F37 to 220.
• Corrected combining class for U+0F71 to 129.
• Added a decomposition for U+0F0C TIBETAN MARK DELIMITER TSHEG BSTAR.
• Added  decompositions for several Greek symbol letters: U+03D0..U+03D2, U+03D5, U+03D6, U+03F0..U+03F2.
• Removed  decompositions from the conjoining jamo block: U+1100..U+11F8.
• Changes to decomposition mappings for some Tibetan vowels for consistency in normalization. (U+0F71, U+0F73, U+0F77, U+0F79, U+0F81)
• Updated the decomposition mappings for several Vietnamese characters with two diacritics (U+1EAC, U+1EAD, U+1EB6, U+1EB7, U+1EC6, U+1EC7, U+1ED8, U+1ED9), so that the recursive decomposition can be generated directly in canonically reordered form (not a normative change).
• Updated the decomposition mappings for several Arabic compatibility characters involving shadda (U+FC5E..U+FC62, U+FCF2..U+FCF4), and two Latin characters (U+1E1C, U+1E1D), so that the decompositions are generated directly in canonically reordered form (not a normative change).
• Changed BIDI category for: U+00A0 NO-BREAK SPACE, U+2007 FIGURE SPACE, U+2028 LINE SEPARATOR.
• Changed BIDI category for extenders of General Category Lm: U+3005, U+3021..U+3035, U+FF9E, U+FF9F.
• Changed General Category and BIDI category for the Greek numeral signs: U+0374, U+0375.
• Corrected General Category for U+FFE8 HALFWIDTH FORMS LIGHT VERTICAL.
• Added Unicode 1.0 names for many Tibetan characters (informative).

Unicode 2.1.8

Modifications made for Version 2.1.8 of UnicodeData.txt include:

• Added combining class 240 for U+0345 COMBINING GREEK YPOGEGRAMMENI so that decompositions involving iota subscript are derivable directly in canonically reordered form; this also has a bearing on simplification of casing of polytonic Greek.
• Changes in decompositions related to Greek tonos. These result from the clarification that monotonic Greek "tonos" should be equated with U+0301 COMBINING ACUTE, rather than with U+030D COMBINING VERTICAL LINE ABOVE. (All Greek characters in the Greek block involving "tonos"; some Greek characters in the polytonic Greek in the 1FXX block.)
• Changed decompositions involving dialytika tonos. (U+0390, U+03B0)
• Changed ternary decompositions to binary. (U+0CCB, U+FB2C, U+FB2D) These changes simplify normalization.
• Removed canonical decomposition for Latin Candrabindu. (U+0310)
• Corrected error in canonical decomposition for U+1FF4.
• Added compatibility decompositions to clarify collation tables. (U+2100, U+2101, U+2105, U+2106, U+1E9A)
• A series of general category changes to assist the convergence of the Unicode definition of identifier with ISO TR 10176:
  • So > Lo: U+0950, U+0AD0, U+0F00, U+0F88..U+0F8B
  • Po > Lo: U+0E2F, U+0EAF, U+3006
  • Lm > Sk: U+309B, U+309C
  • Po > Pc: U+30FB, U+FF65
  • Ps/Pe > Mn: U+0F3E, U+0F3F
• A series of bidi property changes for consistency.
  • L > ET: U+09F2, U+09F3
  • ON > L: U+3007
  • L > ON: U+0F3A..U+0F3D, U+037E, U+0387
• Add case mapping: U+01A6 <-> U+0280
• Updated symmetric swapping value for guillemets: U+00AB, U+00BB, U+2039, U+203A.
• Changes to combining class values. Most Indic fixed position class non-spacing marks were changed to combining class 0. This fixes some inconsistencies in how canonical reordering would apply to Indic scripts, including Tibetan. Indic interacting top/bottom fixed position classes were merged into single (non-zero) classes as part of this change. Tibetan subjoined consonants are changed from combining class 6 to combining class 0. Thai pinthu (U+0E3A) moved to combining class 9. Moved two Devanagari stress marks into generic above and below combining classes (U+0951, U+0952).
• Corrected placement of semicolon near symmetric swapping field. (U+FA0E, etc., scattered positions to U+FA29)

Version 2.1.7

This version was for internal change tracking only, and never publicly released.

Version 2.1.6

This version was for internal change tracking only, and never publicly released.

Unicode 2.1.5

Modifications made for Version 2.1.5 of UnicodeData.txt include:

• Changed decomposition for U+FF9E and U+FF9F so that correct collation weighting will automatically result from the canonical equivalences.
• Removed canonical decompositions for U+04D4, U+04D5, U+04D8, U+04D9, U+04E0, U+04E1, U+04E8, U+04E9 (the implication being that no canonical equivalence is claimed between these 8 characters and similar Latin letters), and updated 4 canonical decompositions for U+04DB, U+04DC, U+04EA, U+04EB to reflect the implied difference in the base character.
• Added Pi, and Pf categories and assigned the relevant quotation marks to those categories, based on the Unicode Technical Corrigendum on Quotation Characters.
• Updating of many bidi properties, following the advice of the ad hoc committee on bidi, and to make the bidi properties of compatibility characters more consistent.
• Changed category of several Tibetan characters: U+0F3E, U+0F3F, U+0F88..U+0F8B to make them non-combining, reflecting the combined opinion of Tibetan experts.
• Added case mapping for U+03F2.
• Corrected case mapping for U+0275.
• Added titlecase mappings for U+03D0, U+03D1, U+03D5, U+03D6, U+03F0.. U+03F2.
• Corrected compatibility label for U+2121.
• Add specific entries for all the CJK compatibility ideographs, U+F900..U+FA2D, so the canonical decomposition for each (the URO character it is equivalent to) can be carried in the database.

Version 2.1.4

This version was for internal change tracking only, and never publicly released.

Version 2.1.3

This version was for internal change tracking only, and never publicly released.

Unicode 2.1.2

Modifications made in updating UnicodeData.txt to Version 2.1.2 for the Unicode Standard, Version 2.1 (from Version 2.0) include:

• Added two characters (U+20AC and U+FFFC).
• Amended bidi properties for U+0026, U+002E, U+0040, U+2007.
• Corrected case mappings for U+018E, U+019F, U+01DD, U+0258, U+0275, U+03C2, U+1E9B.
• Changed combining order class for U+0F71.
• Corrected canonical decompositions for U+0F73, U+1FBE.
• Changed decomposition for U+FB1F from compatibility to canonical.
• Added compatibility decompositions for U+FBE8, U+FBE9, U+FBF9..U+FBFB.
• Corrected compatibility decompositions for U+2469, U+246A, U+3358.

Version 2.1.1

This version was for internal change tracking only, and never publicly released.

Unicode 2.0.0

The modifications made in updating UnicodeData.txt for the Unicode Standard, Version 2.0 include:

• Fixed decompositions with TONOS to use correct NSM: 030D.
• Removed old Hangul Syllables; mapping to new characters are in a separate table.
• Marked compatibility decompositions with additional tags.
• Changed old tag names for clarity.
• Revision of decompositions to use first-level decomposition, instead of maximal decomposition.
• Correction of all known errors in decompositions from earlier versions.
• Added control code names (as old Unicode names).
• Added Hangul Jamo decompositions.
• Added Number category to match properties list in book.
• Fixed categories of Koranic Arabic marks.
• Fixed categories of precomposed characters to match decomposition where possible.
• Added Hebrew cantillation marks and the Tibetan script.
• Added place holders for ranges such as CJK Ideographic Area and the Private Use Area.
• Added categories Me, Sk, Pc, Nl, Cs, Cf, and rectified a number of mistakes in the database.

UCD Terms of Use

For terms of use, see http://www.unicode.org/terms_of_use.html.