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31 <h1>Unicode Data File Format</h1>
32 <table border="1" cellspacing="2" cellpadding="0" height="87" width="100%">
34 <td valign="TOP" width="144">Revision</td>
35 <td valign="TOP">3.1.0</td>
38 <td valign="TOP" width="144">Authors</td>
39 <td valign="TOP">Mark Davis and Ken Whistler</td>
42 <td valign="TOP" width="144">Date</td>
43 <td valign="TOP">2001-02-28</td>
46 <td valign="TOP" width="144">This Version</td>
48 href="http://www.unicode.org/Public/3.1-Update/UnicodeData-3.1.0.html">http://www.unicode.org/Public/3.1-Update/UnicodeData-3.1.0.html</a></td>
51 <td valign="TOP" width="144">Previous Version</td>
53 href="http://www.unicode.org/Public/3.0-Update1/UnicodeData-3.0.1.html">http://www.unicode.org/Public/3.0-Update1/UnicodeData-3.0.1.html</a></td>
56 <td valign="TOP" width="144">Latest Version</td>
58 href="http://www.unicode.org/Public/UNIDATA/UnicodeData.html">http://www.unicode.org/Public/UNIDATA/UnicodeData.html</a></td>
64 <p><i>This document describes the format and content of the UnicodeData.txt
65 file in the Unicode Character Database (UCD).</i></p>
67 <h3><i>Status</i></h3>
69 <p><i>The file and the files described herein are part of the Unicode
70 Character Database and governed by the <a href="#UCD_Terms">UCD Terms of
71 Use</a> given below.</i></p>
72 <p><i>For general information on file formats and table formats, and the
73 implications of normative vs informative properties, see
74 UnicodeCharacterDatabase.html. </i></p>
75 <p><i><b>Warning: </b>the information in this file does not completely
76 describe the use and interpretation of Unicode character properties and
77 behavior. It must be used in conjunction with the data in the other files in
78 the UCD, and relies on the notation and definitions supplied in <a
79 href="http://www.unicode.org/unicode/standard/versions/Unicode3.0.html">The
80 Unicode Standard</a>. All chapter references are to Version 3.1.0 of the
84 <p>This document describes the format of the UnicodeData.txt file, which is one
85 of the files in the Unicode Character Database. The document is divided into the
88 <li><a href="#Field Formats">Field Formats</a>
90 <li><a href="#General Category">General Category</a></li>
91 <li><a href="#Bidirectional Category">Bidirectional Category</a></li>
92 <li><a href="#Character Decomposition">Character Decomposition Mapping</a></li>
93 <li><a href="#Canonical Combining Classes">Canonical Combining Classes</a></li>
94 <li><a href="#Decompositions and Normalization">Decompositions and
95 Normalization</a></li>
96 <li><a href="#Case Mappings">Case Mappings</a></li>
99 <li><a href="#Property Invariants">Property Invariants</a></li>
100 <li><a href="#Modification History">Modification History</a></li>
102 <h2><a name="Field Formats"></a>Field Formats</h2>
103 <p>Each line represents the data for one encoded character in the Unicode
104 Standard. (For information on the file format, see UCD File Format in
105 UnicodeCharacterDatabase.html).
106 <p>Every encoded character has a data entry, with the exception of certain
107 special ranges, as detailed below.
109 <li>These ranges represented only by their start and end characters, since the
110 properties in the file are uniform, except for code values (which are all
111 sequential and assigned).</li>
112 <li>The names of CJK ideograph characters and the names and decompositions of
113 Hangul syllable characters are algorithmically derivable. (See the Unicode
114 Standard and <a href="http://www.unicode.org/unicode/reports/tr15/">Unicode
115 Standard Annex #15</a> for more information).</li>
116 <li>Surrogate code values and private use characters have no names.</li>
117 <li>The supplementary Private Use characters (U+F0000 .. U+FFFFD, U+100000 ..
118 U+10FFFD) are listed as distinct ranges. These correspond to surrogate pairs
119 where the first surrogate is in the High Surrogate Private Use section.</li>
121 <p>The exact ranges represented by start and end characters are:
123 <li>CJK Ideographs Extension A (U+3400 .. U+4DB5)</li>
124 <li>CJK Ideographs (U+4E00 .. U+9FA5)</li>
125 <li>Hangul Syllables (U+AC00 .. U+D7A3)</li>
126 <li>Non-Private Use High Surrogates (U+D800 .. U+DB7F)</li>
127 <li>Private Use High Surrogates (U+DB80 .. U+DBFF)</li>
128 <li>Low Surrogates (U+DC00 .. U+DFFF)</li>
129 <li>The Private Use Area (U+E000 .. U+F8FF)</li>
130 <li>CJK Ideographs Extension B (U+20000 .. U+2A6D6)</li>
131 <li>Plane 15 Private Use Area (U+F0000 .. U+FFFFD)</li>
132 <li>Plane 16 Private Use Area (U+100000 .. U+10FFFD)</li>
134 <p>The following table describes the format and meaning of each field in a data
135 entry in the UnicodeData file.</p>
136 <table border="1" cellspacing="2" cellpadding="2">
138 <th valign="top" align="LEFT">
139 <p align="LEFT">Field</th>
140 <th valign="top" align="LEFT">
141 <p align="LEFT">Name</th>
142 <th valign="top" align="center">
143 <p align="LEFT">N/I</th>
144 <th valign="top" align="LEFT">
145 <p align="LEFT">Explanation</th>
148 <th valign="top">0</th>
149 <td valign="top">Code value</td>
150 <td valign="top" align="center">N</td>
151 <td valign="top">Code value.</td>
154 <th valign="top">1</th>
155 <td valign="top">Character name</td>
156 <td valign="top" align="center">N</td>
157 <td valign="top">These names match exactly the names published in Chapter 14
158 of the Unicode Standard, Version 3.0.</td>
161 <th valign="top">2</th>
162 <td valign="top"><a href="#General Category">General Category</a></td>
163 <td valign="top" align="center">N</td>
164 <td valign="top">This is a useful breakdown into various "character
165 types" which can be used as a default categorization in
166 implementations. See below for a brief explanation.</td>
169 <th valign="top">3</th>
170 <td valign="top"><a href="#Canonical Combining Classes">Canonical Combining
172 <td valign="top" align="center">N</td>
173 <td valign="top">The classes used for the Canonical Ordering Algorithm in
174 the Unicode Standard. These classes are also printed in Chapter 4 of the
175 Unicode Standard.</td>
178 <th valign="top">4</th>
179 <td valign="top"><a href="#Bidirectional Category">Bidirectional Category</a></td>
180 <td valign="top" align="center">N</td>
181 <td valign="top">See the list below for an explanation of the abbreviations
182 used in this field. These are the categories required by the Bidirectional
183 Behavior Algorithm in the Unicode Standard. These categories are
184 summarized in Chapter 3 of the Unicode Standard.</td>
187 <th valign="top">5</th>
188 <td valign="top"><a href="#Character Decomposition">Character Decomposition
190 <td valign="top" align="center">N</td>
191 <td valign="top">In the Unicode Standard, not all of the mappings are full
192 (maximal) decompositions. Recursive application of look-up for
193 decompositions will, in all cases, lead to a maximal decomposition. The
194 decomposition mappings match exactly the decomposition mappings published
195 with the character names in the Unicode Standard.</td>
198 <th valign="top">6</th>
199 <td valign="top">Decimal digit value</td>
200 <td valign="top" align="center">N</td>
201 <td valign="top">This is a numeric field. If the character has the decimal
202 digit property, as specified in Chapter 4 of the Unicode Standard, the
203 value of that digit is represented with an integer value in this field</td>
206 <th valign="top">7</th>
207 <td valign="top">Digit value</td>
208 <td valign="top" align="center">N</td>
209 <td valign="top">This is a numeric field. If the character represents a
210 digit, not necessarily a decimal digit, the value is here. This covers
211 digits which do not form decimal radix forms, such as the compatibility
212 superscript digits</td>
215 <th valign="top">8</th>
216 <td valign="top">Numeric value</td>
217 <td valign="top" align="center">N</td>
218 <td valign="top">This is a numeric field. If the character has the numeric
219 property, as specified in Chapter 4 of the Unicode Standard, the value of
220 that character is represented with an integer or rational number in this
221 field. This includes fractions as, e.g., "1/5" for U+2155 VULGAR
222 FRACTION ONE FIFTH Also included are numerical values for compatibility
223 characters such as circled numbers.</td>
226 <th valign="top">9</th>
227 <td valign="top">Mirrored</td>
228 <td valign="top" align="center">N</td>
229 <td valign="top">If the character has been identified as a
230 "mirrored" character in bidirectional text, this field has the
231 value "Y"; otherwise "N". The list of mirrored
232 characters is also printed in Chapter 4 of the Unicode Standard.</td>
235 <th valign="top">10</th>
236 <td valign="top">Unicode 1.0 Name</td>
237 <td valign="top" align="center">I</td>
238 <td valign="top">This is the old name as published in Unicode 1.0. This name
239 is only provided when it is significantly different from the current name
240 for the character.</td>
243 <th valign="top">11</th>
244 <td valign="top">10646 comment field</td>
245 <td valign="top" align="center">I</td>
246 <td valign="top">This is the ISO 10646 comment field. It appears in
247 parentheses in the 10646 names list, or contains an asterisk to mark an
251 <th valign="top">12</th>
252 <td valign="top"><a href="#Case Mappings">Uppercase Mapping</a></td>
253 <td valign="top" align="center">N</td>
254 <td valign="top">Upper case equivalent mapping. If a character is part of an
255 alphabet with case distinctions, and has a simple upper case equivalent,
256 then the upper case equivalent is in this field. See the explanation below
257 on case distinctions. These mappings are always one-to-one, not
258 one-to-many or many-to-one.
259 <p><i>For full case mappings, see <a
260 href="http://www.unicode.org/unicode/reports/tr21/">UTR #21</a> and
261 SpecialCasing.txt.</i></p>
265 <th valign="top">13</th>
266 <td valign="top"><a href="#Case Mappings">Lowercase Mapping</a></td>
267 <td valign="top" align="center">N</td>
268 <td valign="top">Similar to Uppercase mapping</td>
271 <th valign="top">14</th>
272 <td valign="top"><a href="#Case Mappings">Titlecase Mapping</a></td>
273 <td valign="top" align="center">N</td>
274 <td valign="top">Similar to Uppercase mapping</td>
277 <h3><a name="General Category"></a>General Category</h3>
278 <p>The values in this field are abbreviations for the following values. For more
279 information, see the Unicode Standard.</p>
281 <p><b>Note:</b> the standard does not assign information to control characters
282 (except for certain cases in the Bidirectional Algorithm). Implementations
283 will generally also assign categories to certain control characters, notably
284 CR and LF, according to platform conventions. See <a
285 href="http://www.unicode.org/unicode/reports/tr13/">UAX #13: Unicode Newline
286 Guidelines</a> for more information.</p>
288 <table border="0" cellspacing="0" cellpadding="4">
291 <p align="LEFT">Abbr.</th>
293 <p align="LEFT">Description</th>
296 <td align="CENTER">Lu</td>
297 <td>Letter, Uppercase</td>
300 <td align="CENTER">Ll</td>
301 <td>Letter, Lowercase</td>
304 <td align="CENTER">Lt</td>
305 <td>Letter, Titlecase</td>
308 <td align="CENTER">Lm</td>
309 <td>Letter, Modifier</td>
312 <td align="CENTER">Lo</td>
313 <td>Letter, Other</td>
316 <td align="CENTER">Mn</td>
317 <td>Mark, Non-Spacing</td>
320 <td align="CENTER">Mc</td>
321 <td>Mark, Spacing Combining</td>
324 <td align="CENTER">Me</td>
325 <td>Mark, Enclosing</td>
328 <td align="CENTER">Nd</td>
329 <td>Number, Decimal Digit</td>
332 <td align="CENTER">Nl</td>
333 <td>Number, Letter</td>
336 <td align="CENTER">No</td>
337 <td>Number, Other</td>
340 <td align="CENTER">Pc</td>
341 <td>Punctuation, Connector</td>
344 <td align="CENTER">Pd</td>
345 <td>Punctuation, Dash</td>
348 <td align="CENTER">Ps</td>
349 <td>Punctuation, Open</td>
352 <td align="CENTER">Pe</td>
353 <td>Punctuation, Close</td>
356 <td align="CENTER">Pi</td>
357 <td>Punctuation, Initial quote (may behave like Ps or Pe depending on usage)</td>
360 <td align="CENTER">Pf</td>
361 <td>Punctuation, Final quote (may behave like Ps or Pe depending on usage)</td>
364 <td align="CENTER">Po</td>
365 <td>Punctuation, Other</td>
368 <td align="CENTER">Sm</td>
369 <td>Symbol, Math</td>
372 <td align="CENTER">Sc</td>
373 <td>Symbol, Currency</td>
376 <td align="CENTER">Sk</td>
377 <td>Symbol, Modifier</td>
380 <td align="CENTER">So</td>
381 <td>Symbol, Other</td>
384 <td align="CENTER">Zs</td>
385 <td>Separator, Space</td>
388 <td align="CENTER">Zl</td>
389 <td>Separator, Line</td>
392 <td align="CENTER">Zp</td>
393 <td>Separator, Paragraph</td>
396 <td align="CENTER">Cc</td>
397 <td>Other, Control</td>
400 <td align="CENTER">Cf</td>
401 <td>Other, Format</td>
404 <td align="CENTER">Cs</td>
405 <td>Other, Surrogate</td>
408 <td align="CENTER">Co</td>
409 <td>Other, Private Use</td>
412 <td align="CENTER">Cn</td>
413 <td>Other, Not Assigned (no characters in the file have this property)</td>
417 <p><b>Note:</b> The term "L&" is sometimes used to stand for
418 Uppercase, Lowercase or Titlecase letters (Lu, Ll, or Lt).</p>
420 <h3><a name="Bidirectional Category"></a>Bidirectional Category</h3>
421 <p>Please refer to Chapter 3 for an explanation of the algorithm for
422 Bidirectional Behavior and an explanation of the significance of these
423 categories. An up-to-date version can be found on <a
424 href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9:
425 The Bidirectional Algorithm</a>.</p>
426 <table border="0" cellpadding="4" cellspacing="0">
428 <th valign="TOP" align="LEFT">
429 <p align="LEFT">Type</th>
430 <th valign="TOP" align="LEFT">
431 <p align="LEFT">Description</th>
434 <td valign="TOP"><b>L</b></td>
435 <td valign="TOP">Left-to-Right</td>
438 <td valign="TOP"><b>LRE</b></td>
439 <td valign="TOP">Left-to-Right Embedding</td>
442 <td valign="TOP"><b>LRO</b></td>
443 <td valign="TOP">Left-to-Right Override</td>
446 <td valign="TOP"><b>R</b></td>
447 <td valign="TOP">Right-to-Left</td>
450 <td valign="TOP"><b>AL</b></td>
451 <td valign="TOP">Right-to-Left Arabic</td>
454 <td valign="TOP"><b>RLE</b></td>
455 <td valign="TOP">Right-to-Left Embedding</td>
458 <td valign="TOP"><b>RLO</b></td>
459 <td valign="TOP">Right-to-Left Override</td>
462 <td valign="TOP"><b>PDF</b></td>
463 <td valign="TOP">Pop Directional Format</td>
466 <td valign="TOP"><b>EN</b></td>
467 <td valign="TOP">European Number</td>
470 <td valign="TOP"><b>ES</b></td>
471 <td valign="TOP">European Number Separator</td>
474 <td valign="TOP"><b>ET</b></td>
475 <td valign="TOP">European Number Terminator</td>
478 <td valign="TOP"><b>AN</b></td>
479 <td valign="TOP">Arabic Number</td>
482 <td valign="TOP"><b>CS</b></td>
483 <td valign="TOP">Common Number Separator</td>
486 <td valign="TOP"><b>NSM</b></td>
487 <td valign="TOP">Non-Spacing Mark</td>
490 <td valign="TOP"><b>BN</b></td>
491 <td valign="TOP">Boundary Neutral</td>
494 <td valign="TOP"><b>B</b></td>
495 <td valign="TOP">Paragraph Separator</td>
498 <td valign="TOP"><b>S</b></td>
499 <td valign="TOP">Segment Separator</td>
502 <td valign="TOP"><b>WS</b></td>
503 <td valign="TOP">Whitespace</td>
506 <td valign="TOP"><b>ON</b></td>
507 <td valign="TOP">Other Neutrals</td>
510 <h3><a name="Character Decomposition"></a>Character Decomposition Mapping</h3>
511 <p>The tags supplied with certain decomposition mappings generally indicate
512 formatting information. Where no such tag is given, the mapping is designated as
513 canonical. Conversely, the presence of a formatting tag also indicates that the
514 mapping is a compatibility mapping and not a canonical mapping. In the absence
515 of other formatting information in a compatibility mapping, the tag is used to
516 distinguish it from canonical mappings.</p>
517 <p>In some instances a canonical mapping or a compatibility mapping may consist
518 of a single character. For a canonical mapping, this indicates that the
519 character is a canonical equivalent of another single character. For a
520 compatibility mapping, this indicates that the character is a compatibility
521 equivalent of another single character. The compatibility formatting tags used
523 <table border="0" cellspacing="0" cellpadding="4">
527 <p align="LEFT">Description</th>
530 <td align="CENTER"><font> </td>
531 <td>A font variant (e.g. a blackletter form).</td>
534 <td align="CENTER"><noBreak> </td>
535 <td>A no-break version of a space or hyphen.</td>
538 <td align="CENTER"><initial> </td>
539 <td>An initial presentation form (Arabic).</td>
542 <td align="CENTER"><medial> </td>
543 <td>A medial presentation form (Arabic).</td>
546 <td align="CENTER"><final> </td>
547 <td>A final presentation form (Arabic).</td>
550 <td align="CENTER"><isolated> </td>
551 <td>An isolated presentation form (Arabic).</td>
554 <td align="CENTER"><circle> </td>
555 <td>An encircled form.</td>
558 <td align="CENTER"><super> </td>
559 <td>A superscript form.</td>
562 <td align="CENTER"><sub> </td>
563 <td>A subscript form.</td>
566 <td align="CENTER"><vertical> </td>
567 <td>A vertical layout presentation form.</td>
570 <td align="CENTER"><wide> </td>
571 <td>A wide (or zenkaku) compatibility character.</td>
574 <td align="CENTER"><narrow> </td>
575 <td>A narrow (or hankaku) compatibility character.</td>
578 <td align="CENTER"><small> </td>
579 <td>A small variant form (CNS compatibility).</td>
582 <td align="CENTER"><square> </td>
583 <td>A CJK squared font variant.</td>
586 <td align="CENTER"><fraction> </td>
587 <td>A vulgar fraction form.</td>
590 <td align="CENTER"><compat> </td>
591 <td>Otherwise unspecified compatibility character.</td>
594 <p><b>Reminder: </b>There is a difference between decomposition and
595 decomposition mapping. The decomposition mappings are defined in the UnicodeData,
596 while the decomposition (also termed "full decomposition") is defined
597 in Chapter 3 to use those mappings <i>recursively.</i>
599 <li>The canonical decomposition is formed by recursively applying the
600 canonical mappings, then applying the canonical reordering algorithm.</li>
601 <li>The compatibility decomposition is formed by recursively applying the
602 canonical <em>and</em> compatibility mappings, then applying the canonical
603 reordering algorithm.</li>
605 <h3><a name="Canonical Combining Classes"></a>Canonical Combining Classes</h3>
606 <table border="0" cellspacing="0" cellpadding="4">
609 <p align="LEFT">Value</th>
611 <p align="LEFT">Description</th>
614 <td align="RIGHT">0:</td>
615 <td>Spacing, split, enclosing, reordrant, and Tibetan subjoined</td>
618 <td align="RIGHT">1:</td>
619 <td>Overlays and interior</td>
622 <td align="RIGHT">7:</td>
626 <td align="RIGHT">8:</td>
627 <td>Hiragana/Katakana voicing marks</td>
630 <td align="RIGHT">9:</td>
634 <td align="RIGHT">10:</td>
635 <td>Start of fixed position classes</td>
638 <td align="RIGHT">199:</td>
639 <td>End of fixed position classes</td>
642 <td align="RIGHT">200:</td>
643 <td>Below left attached</td>
646 <td align="RIGHT">202:</td>
647 <td>Below attached</td>
650 <td align="RIGHT">204:</td>
651 <td>Below right attached</td>
654 <td align="RIGHT">208:</td>
655 <td>Left attached (reordrant around single base character)</td>
658 <td align="RIGHT">210:</td>
659 <td>Right attached</td>
662 <td align="RIGHT">212:</td>
663 <td>Above left attached</td>
666 <td align="RIGHT">214:</td>
667 <td>Above attached</td>
670 <td align="RIGHT">216:</td>
671 <td>Above right attached</td>
674 <td align="RIGHT">218:</td>
678 <td align="RIGHT">220:</td>
682 <td align="RIGHT">222:</td>
686 <td align="RIGHT">224:</td>
687 <td>Left (reordrant around single base character)</td>
690 <td align="RIGHT">226:</td>
694 <td align="RIGHT">228:</td>
698 <td align="RIGHT">230:</td>
702 <td align="RIGHT">232:</td>
706 <td align="RIGHT">233:</td>
707 <td>Double below</td>
710 <td align="RIGHT">234:</td>
711 <td>Double above</td>
714 <td align="RIGHT">240:</td>
715 <td>Below (iota subscript)</td>
718 <p><strong>Note: </strong>some of the combining classes in this list do not
719 currently have members but are specified here for completeness.</p>
720 <h3><a name="Decompositions and Normalization"></a>Decompositions and
722 <p>Decomposition is specified in Chapter 3. <a
723 href="http://www.unicode.org/unicode/reports/tr15/"><i>Unicode Standard Annex
724 #15: Unicode Normalization Forms</i></a> specifies the interaction between
725 decomposition and normalization. That report specifies how the decompositions
726 defined in UnicodeData.txt are used to derive normalized forms of Unicode text.</p>
727 <p>Note that as of the 2.1.9 update of the Unicode Character Database, the
728 decompositions in the UnicodeData.txt file can be used to recursively derive the
729 full decomposition in canonical order, without the need to separately apply
730 canonical reordering. However, canonical reordering of combining character
731 sequences <b><i>must</i></b> still be applied in decomposition when normalizing
732 source text which contains any combining marks.</p>
733 <h3><a name="Case Mappings"></a>Case Mappings</h3>
734 <p>There are a number of complications to case mappings that occur once the
735 repertoire of characters is expanded beyond ASCII. For more information, see <a
736 href="http://www.unicode.org/unicode/reports/tr21/">UTR #21: Case Mappings</a>.</p>
737 <p>For compatibility with existing parsers, UnicodeData.txt only contains case
738 mappings for characters where they are one-to-one mappings; it also omits
739 information about context-sensitive case mappings. Information about these
740 special cases can be found in a separate data file, SpecialCasing.txt.</p>
741 <h2><a name="Property Invariants"></a>Property Invariants</h2>
742 <p>Values in UnicodeData.txt are subject to correction as errors are found;
743 however, some characteristics of the categories themselves can be considered
744 invariants. Applications may wish to take these invariants into account when
745 choosing how to implement character properties. For more information, see <a
746 href="http://www.unicode.org/unicode/standard/policies.html">Unicode Policies</a>.</p>
747 <p>The following is a partial list of known invariants for the Unicode Character
749 <h4>Database Fields</h4>
751 <li>The number of fields in UnicodeData.txt is fixed.</li>
752 <li>The order of the fields is also fixed.
754 <li>Any additional information about character properties to be added in
755 the future will appear in separate data tables, rather than being added
756 on to the existing table or by subdivision or reinterpretation of
757 existing fields.</li>
761 <h4>General Category</h4>
763 <li>There will never be more than 32 General Category values.
765 <li>It is very unlikely that the Unicode Technical Committee will
766 subdivide the General Category partition any further, since that can
767 cause implementations to misbehave. Because the General Category is
768 limited to 32 values, 5 bits can be used to represent the information,
769 and a 32-bit integer can be used as a bitmask to represent arbitrary
770 sets of categories.</li>
774 <h4>Combining Classes</h4>
776 <li>Combining classes are limited to the values 0 to 255.
778 <li>In practice, there are far fewer than 256 values used. Implementations
779 may take advantage of this fact for compression, since only the ordering
780 of the non-zero values matters for the Canonical Reordering Algorithm.
781 It is possible for up to 256 values to be used in the future; however,
782 UTC decisions in the future may restrict the number of values to 128,
783 since this has implementation advantages. [Signed bytes can be used
784 without widening to ints in Java, for example.]</li>
787 <li>All characters other than those of General Category M* have the combining
790 <li>Currently, all characters other than those of General Category Mn have
791 the value 0. However, some characters of General Category Me or Mc may
792 be given non-zero values in the future.</li>
793 <li>The precise values above the value 0 are not invariant--only the
794 relative ordering is considered normative. For example, it is not
795 guaranteed in future versions that the class of U+05B4 will be precisely
800 <h4>Canonical Decomposition</h4>
802 <li>Canonical mappings are always in canonical order.</li>
803 <li>Canonical mappings have only the first of a pair possibly further
805 <li>Canonical decompositions are "transparent" to other character
808 <li><tt>BIDI(a) = BIDI(principal(canonicalDecomposition(a))</tt></li>
809 <li><tt>Category(a) = Category(principal(canonicalDecomposition(a))</tt></li>
810 <li><tt>CombiningClass(a) =
811 CombiningClass(principal(canonicalDecomposition(a))</tt><br>
812 where principal(a) is the first character not of type Mn, or the first
813 character if all characters are of type Mn.</li>
816 <li>However, because there are sometimes missing case pairs, and because of
817 some legacy characters, it is only generally true that:
819 <li><tt>upper(canonicalDecomposition(a)) = canonicalDecomposition(upper(a))</tt></li>
820 <li><tt>lower(canonicalDecomposition(a)) = canonicalDecomposition(lower(a))</tt></li>
821 <li><tt>title(canonicalDecomposition(a)) = canonicalDecomposition(title(a))</tt></li>
825 <h2><a name="Modification History"></a>Modification History</h2>
826 <p>This section provides a summary of the changes between update versions of the
827 Unicode Standard.</p>
829 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 3.1">Unicode
831 <p>Modifications made for Version 3.0.1 of UnicodeData.txt include:
833 <li>Addition of 2237 new entries, to cover new characters and new ranges of
834 unified Han characters encoded in Unicode 3.1.</li>
835 <li>Changed General Category value of 16EE..16F0 (Runic golden numbers) from
839 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 3.0.1">Unicode
841 <p>Modifications made for Version 3.0.1 of UnicodeData.txt include:
843 <li>Added 5- and 6-digit representation of code points past U+FFFF.</li>
844 <li>Added Private Use range definitions for Planes 15 and 16.</li>
845 <li>Minor additions for the 10646 comment field.</li>
848 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 3.0.0">Unicode
850 <p>Modifications made for Version 3.0.0 of UnicodeData.txt include many new
851 characters and a number of property changes. These are summarized in Appendex D
852 of <em>The Unicode Standard, Version 3.0.</em></p>
854 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 2.1.9">Unicode
856 <p>Modifications made for Version 2.1.9 of UnicodeData.txt include:
858 <li>Corrected combining class for U+05AE HEBREW ACCENT ZINOR.</li>
859 <li>Corrected combining class for U+20E1 COMBINING LEFT RIGHT ARROW ABOVE</li>
860 <li>Corrected combining class for U+0F35 and U+0F37 to 220.</li>
861 <li>Corrected combining class for U+0F71 to 129.</li>
862 <li>Added a decomposition for U+0F0C TIBETAN MARK DELIMITER TSHEG BSTAR.</li>
863 <li>Added decompositions for several Greek symbol letters:
864 U+03D0..U+03D2, U+03D5, U+03D6, U+03F0..U+03F2.</li>
865 <li>Removed decompositions from the conjoining jamo block:
867 <li>Changes to decomposition mappings for some Tibetan vowels for consistency
868 in normalization. (U+0F71, U+0F73, U+0F77, U+0F79, U+0F81)</li>
869 <li>Updated the decomposition mappings for several Vietnamese characters with
870 two diacritics (U+1EAC, U+1EAD, U+1EB6, U+1EB7, U+1EC6, U+1EC7, U+1ED8,
871 U+1ED9), so that the recursive decomposition can be generated directly in
872 canonically reordered form (not a normative change).</li>
873 <li>Updated the decomposition mappings for several Arabic compatibility
874 characters involving shadda (U+FC5E..U+FC62, U+FCF2..U+FCF4), and two Latin
875 characters (U+1E1C, U+1E1D), so that the decompositions are generated
876 directly in canonically reordered form (not a normative change).</li>
877 <li>Changed BIDI category for: U+00A0 NO-BREAK SPACE, U+2007 FIGURE SPACE,
878 U+2028 LINE SEPARATOR.</li>
879 <li>Changed BIDI category for extenders of General Category Lm: U+3005,
880 U+3021..U+3035, U+FF9E, U+FF9F.</li>
881 <li>Changed General Category and BIDI category for the Greek numeral signs:
883 <li>Corrected General Category for U+FFE8 HALFWIDTH FORMS LIGHT VERTICAL.</li>
884 <li>Added Unicode 1.0 names for many Tibetan characters (informative).</li>
887 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 2.1.8">Unicode
889 <p>Modifications made for Version 2.1.8 of UnicodeData.txt include:
891 <li>Added combining class 240 for U+0345 COMBINING GREEK YPOGEGRAMMENI so that
892 decompositions involving iota subscript are derivable directly in
893 canonically reordered form; this also has a bearing on simplification of
894 casing of polytonic Greek.</li>
895 <li>Changes in decompositions related to Greek tonos. These result from the
896 clarification that monotonic Greek "tonos" should be equated with
897 U+0301 COMBINING ACUTE, rather than with U+030D COMBINING VERTICAL LINE
898 ABOVE. (All Greek characters in the Greek block involving "tonos";
899 some Greek characters in the polytonic Greek in the 1FXX block.)</li>
900 <li>Changed decompositions involving dialytika tonos. (U+0390, U+03B0)</li>
901 <li>Changed ternary decompositions to binary. (U+0CCB, U+FB2C, U+FB2D) These
902 changes simplify normalization.</li>
903 <li>Removed canonical decomposition for Latin Candrabindu. (U+0310)</li>
904 <li>Corrected error in canonical decomposition for U+1FF4.</li>
905 <li>Added compatibility decompositions to clarify collation tables. (U+2100,
906 U+2101, U+2105, U+2106, U+1E9A)</li>
907 <li>A series of general category changes to assist the convergence of of
908 Unicode definition of identifier with ISO TR 10176:
910 <li>So > Lo: U+0950, U+0AD0, U+0F00, U+0F88..U+0F8B</li>
911 <li>Po > Lo: U+0E2F, U+0EAF, U+3006</li>
912 <li>Lm > Sk: U+309B, U+309C</li>
913 <li>Po > Pc: U+30FB, U+FF65</li>
914 <li>Ps/Pe > Mn: U+0F3E, U+0F3F</li>
917 <li>A series of bidi property changes for consistency.
919 <li>L > ET: U+09F2, U+09F3</li>
920 <li>ON > L: U+3007</li>
921 <li>L > ON: U+0F3A..U+0F3D, U+037E, U+0387</li>
924 <li>Add case mapping: U+01A6 <-> U+0280</li>
925 <li>Updated symmetric swapping value for guillemets: U+00AB, U+00BB, U+2039,
927 <li>Changes to combining class values. Most Indic fixed position class
928 non-spacing marks were changed to combining class 0. This fixes some
929 inconsistencies in how canonical reordering would apply to Indic scripts,
930 including Tibetan. Indic interacting top/bottom fixed position classes were
931 merged into single (non-zero) classes as part of this change. Tibetan
932 subjoined consonants are changed from combining class 6 to combining class
933 0. Thai pinthu (U+0E3A) moved to combining class 9. Moved two Devanagari
934 stress marks into generic above and below combining classes (U+0951,
936 <li>Corrected placement of semicolon near symmetric swapping field. (U+FA0E,
937 etc., scattered positions to U+FA29)</li>
939 <h3>Version 2.1.7</h3>
940 <p><i>This version was for internal change tracking only, and never publicly
942 <h3>Version 2.1.6</h3>
943 <p><i>This version was for internal change tracking only, and never publicly
946 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 2.1.5">Unicode
948 <p>Modifications made for Version 2.1.5 of UnicodeData.txt include:
950 <li>Changed decomposition for U+FF9E and U+FF9F so that correct collation
951 weighting will automatically result from the canonical equivalences.</li>
952 <li>Removed canonical decompositions for U+04D4, U+04D5, U+04D8, U+04D9,
953 U+04E0, U+04E1, U+04E8, U+04E9 (the implication being that no canonical
954 equivalence is claimed between these 8 characters and similar Latin
955 letters), and updated 4 canonical decompositions for U+04DB, U+04DC, U+04EA,
956 U+04EB to reflect the implied difference in the base character.</li>
957 <li>Added Pi, and Pf categories and assigned the relevant quotation marks to
958 those categories, based on the Unicode Technical Corrigendum on Quotation
960 <li>Updating of many bidi properties, following the advice of the ad hoc
961 committee on bidi, and to make the bidi properties of compatibility
962 characters more consistent.</li>
963 <li>Changed category of several Tibetan characters: U+0F3E, U+0F3F,
964 U+0F88..U+0F8B to make them non-combining, reflecting the combined opinion
965 of Tibetan experts.</li>
966 <li>Added case mapping for U+03F2.</li>
967 <li>Corrected case mapping for U+0275.</li>
968 <li>Added titlecase mappings for U+03D0, U+03D1, U+03D5, U+03D6, U+03F0..
970 <li>Corrected compatibility label for U+2121.</li>
971 <li>Add specific entries for all the CJK compatibility ideographs,
972 U+F900..U+FA2D, so the canonical decomposition for each (the URO character
973 it is equivalent to) can be carried in the database.</li>
975 <h3>Version 2.1.4</h3>
976 <p><i>This version was for internal change tracking only, and never publicly
978 <h3>Version 2.1.3</h3>
979 <p><i>This version was for internal change tracking only, and never publicly
982 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 2.1.2">Unicode
984 <p>Modifications made in updating UnicodeData.txt to Version 2.1.2 for the
985 Unicode Standard, Version 2.1 (from Version 2.0) include:
987 <li>Added two characters (U+20AC and U+FFFC).</li>
988 <li>Amended bidi properties for U+0026, U+002E, U+0040, U+2007.</li>
989 <li>Corrected case mappings for U+018E, U+019F, U+01DD, U+0258, U+0275,
991 <li>Changed combining order class for U+0F71.</li>
992 <li>Corrected canonical decompositions for U+0F73, U+1FBE.</li>
993 <li>Changed decomposition for U+FB1F from compatibility to canonical.</li>
994 <li>Added compatibility decompositions for U+FBE8, U+FBE9, U+FBF9..U+FBFB.</li>
995 <li>Corrected compatibility decompositions for U+2469, U+246A, U+3358.</li>
997 <h3>Version 2.1.1</h3>
998 <p><i>This version was for internal change tracking only, and never publicly
1001 href="http://www.unicode.org/unicode/standard/versions/enumeratedversions.html#Unicode 2.0.0">Unicode
1003 <p>The modifications made in updating UnicodeData.txt for the Unicode Standard,
1004 Version 2.0 include:
1006 <li>Fixed decompositions with TONOS to use correct NSM: 030D.</li>
1007 <li>Removed old Hangul Syllables; mapping to new characters are in a separate
1009 <li>Marked compatibility decompositions with additional tags.</li>
1010 <li>Changed old tag names for clarity.</li>
1011 <li>Revision of decompositions to use first-level decomposition, instead of
1012 maximal decomposition.</li>
1013 <li>Correction of all known errors in decompositions from earlier versions.</li>
1014 <li>Added control code names (as old Unicode names).</li>
1015 <li>Added Hangul Jamo decompositions.</li>
1016 <li>Added Number category to match properties list in book.</li>
1017 <li>Fixed categories of Koranic Arabic marks.</li>
1018 <li>Fixed categories of precomposed characters to match decomposition where
1020 <li>Added Hebrew cantillation marks and the Tibetan script.</li>
1021 <li>Added place holders for ranges such as CJK Ideographic Area and the
1022 Private Use Area.</li>
1023 <li>Added categories Me, Sk, Pc, Nl, Cs, Cf, and rectified a number of
1024 mistakes in the database.</li>
1026 <h2><i><a name="UCD_Terms">UCD Terms of Use</a></i></h2>
1027 <h3><i>Disclaimer</i></h3>
1029 <p><i>The Unicode Character Database is provided as is by Unicode, Inc. No
1030 claims are made as to fitness for any particular purpose. No warranties of any
1031 kind are expressed or implied. The recipient agrees to determine applicability
1032 of information provided. If this file has been purchased on magnetic or
1033 optical media from Unicode, Inc., the sole remedy for any claim will be
1034 exchange of defective media within 90 days of receipt.</i></p>
1035 <p><i>This disclaimer is applicable for all other data files accompanying the
1036 Unicode Character Database, some of which have been compiled by the Unicode
1037 Consortium, and some of which have been supplied by other sources.</i></p>
1039 <h3><i>Limitations on Rights to Redistribute This Data</i></h3>
1041 <p><i>Recipient is granted the right to make copies in any form for internal
1042 distribution and to freely use the information supplied in the creation of
1043 products supporting the Unicode<sup>TM</sup> Standard. The files in the
1044 Unicode Character Database can be redistributed to third parties or other
1045 organizations (whether for profit or not) as long as this notice and the
1046 disclaimer notice are retained. Information can be extracted from these files
1047 and used in documentation or programs, as long as there is an accompanying
1048 notice indicating the source.</i></p>
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