DerivedProperties-3.1.1.html
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<h1>Derived Character Properties</h1>
<table height="87" cellspacing="2" cellpadding="0" width="100%" border="1">
<tbody>
<tr>
<td valign="top" width="144">Revision</td>
<td valign="top">3.1.1</td>
</tr>
<tr>
<td valign="top" width="144">Authors</td>
<td valign="top">Mark Davis</td>
</tr>
<tr>
<td valign="top" width="144">Date</td>
<td valign="top">2001-08-08</td>
</tr>
<tr>
<td valign="top" width="144">This Version</td>
<td valign="top"><a href="http://www.unicode.org/Public/3.1-Update1/DerivedProperties-3.1.1.html">http://www.unicode.org/Public/3.1-Update/DerivedProperties-3.1.0.html</a></td>
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<tr>
<td valign="top" width="144">Previous Version</td>
<td valign="top"><a href="http://www.unicode.org/Public/3.1-Update/DerivedProperties-3.1.0.html">http://www.unicode.org/Public/3.1-Update/DerivedProperties-3.1.0.html</a></td>
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<tr>
<td valign="top" width="144">Latest Version</td>
<td valign="top"><a href="http://www.unicode.org/Public/UNIDATA/DerivedProperties.html">http://www.unicode.org/Public/UNIDATA/DerivedProperties.html</a></td>
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<h3><br>
S<i>ummary</i></h3>
<blockquote>
<p><i>This document describes the format and content of the main derived data
files in the Unicode Character Database (UCD).</i></p>
</blockquote>
<h3><i>Status</i></h3>
<blockquote>
<p><i>The file and the files described herein are part of the Unicode
Character Database and governed by the <a href="#UCD_Terms">UCD Terms of Use</a>
given below.</i></p>
<p><i>For general information on file formats and table formats, and the
implications of normative vs informative properties, see
UnicodeCharacterDatabase.html.</i></p>
<p><i><b>Warning: </b>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 UCD, and relies on the notation and definitions supplied in <a href="http://www.unicode.org/unicode/standard/versions/Unicode3.0.html">The
Unicode Standard</a>. All chapter references are to Version 3.1.0 of the
standard.</i></p>
</blockquote>
<blockquote>
<hr width="50%">
</blockquote>
<h2>Introduction</h2>
<p align="left">This document describes a number of data files in the Unicode
Character database. These are the Derived data files, containing information
that can be completely derived from other data files, but is presented in a
different format for ease of use.</p>
<p align="left">The files themselves are informative, although they may contain
normative properties. For more information, see UnicodeCharacterDatabase.html.</p>
<h2>Derived Core Properties</h2>
<p>The following are important derived properties of Unicode characters, and are
contained in DerivedCoreProperties.txt.</p>
<div align="center">
<center>
<table border="1" cellspacing="0" cellpadding="3" class="smallText">
<tr>
<th valign="top" align="left">Property Value</th>
<th valign="top">N/I</th>
<th>Definition and Generation</th>
</tr>
<tr>
<th valign="top" align="left">Math</th>
<th valign="top">I</th>
<td valign="top">Characters with the Math property. For more information,
see <a href="http://www.unicode.org/unicode/uni2book/ch04.pdf">Chapter
4, Character Properties</a>.<br>
<i>Generated from: Sm + Other_Math</i></td>
</tr>
<tr>
<th valign="top" align="left">Alphabetic</th>
<th valign="top">I</th>
<td valign="top">Characters with the Alphabetic property. For more
information, see <a href="http://www.unicode.org/unicode/uni2book/ch04.pdf">Chapter
4, Character Properties</a>.<br>
<i>Generated from: Lu+Ll+Lt+Lm+Lo+ Other_Alphabetic</i></td>
</tr>
<tr>
<th valign="top" align="left">Lowercase</th>
<th valign="top">I</th>
<td valign="top">Characters with the Lowercase property. For more
information, see <a href="http://www.unicode.org/unicode/uni2book/ch04.pdf">Chapter
4, Character Properties</a> and <a href="http://www.unicode.org/unicode/reports/tr21/">UTR
#21: Case Mappings</a>.<br>
<i>Generated from: Ll + Other_Lowercase</i></td>
</tr>
<tr>
<th valign="top" align="left">Uppercase</th>
<th valign="top">I</th>
<td valign="top">Characters with the Uppercase property. For more
information, see <a href="http://www.unicode.org/unicode/uni2book/ch04.pdf">Chapter
4, Character Properties</a> and <a href="http://www.unicode.org/unicode/reports/tr21/">UTR
#21: Case Mappings</a>.<br>
<i>Generated from: Lu + Other_Uppercase</i></td>
</tr>
<tr>
<th valign="top" align="left">ID_Start</th>
<th valign="top">I</th>
<td valign="top">Characters that can start an identifier.<br>
<i>Generated from Lu+Ll+Lt+Lm+Lo+Nl</i></td>
</tr>
<tr>
<th valign="top" align="left">ID_Continue</th>
<th valign="top">I</th>
<td valign="top">Characters that can continue an identifier. See <a href="#Cf_Note">Cf
Note</a>.<br>
<i>Generated from: ID_Start + Mn+Mc+Nd+Pc</i></td>
</tr>
<tr>
<th valign="top" align="left">XID_Start</th>
<th valign="top">I</th>
<td valign="top">Same as ID_Start, except for modifications to allow
closure under normalization forms NFKC and NFKD.<br>
<i>Generated from: ID_Start; see <a href="#Closure_Note">Closure Note</a></i></td>
</tr>
<tr>
<th valign="top" align="left">XID_Continue</th>
<th valign="top">I</th>
<td valign="top">Same as ID_Continue, except for modifications to allow
closure under normalization forms NFKC and NFKD. See <a href="#Closure_Note">Closure
Note</a> and <a href="#Cf_Note">Cf Note</a>.<br>
<i>Generated from: ID_Continue; see <a href="#Closure_Note">Closure Note</a></i></td>
</tr>
</table>
</center>
</div>
<blockquote>
<p><b><a name="Closure_Note">Closure Note</a>: </b>XID_Start and XID_Continue
are defined by adding or removing certain special characters as per <a href="http://www.unicode.org/unicode/reports/tr15/#Programming%20Language%20Identifiers">UAX
#15, Annex 7</a>. They do <i><b>not</b></i> remove the non-NFKD nor the
non_NFKC characters; if that is desired it needs to be a separate filter. They
merely ensure that:</p>
<p align="center">if <code>isIdentifer(string)<br>
</code>then <code>isIdentifier(NFKC(string))<br>
</code>and <code>isIdentifier(NFKD(string))</code></p>
<p><b><a name="Cf_Note">Cf Note</a>: </b>The general category Cf characters
are not included in ID_Continue nor in XID_Continue; they should continue
identifiers, but be filtered out of the result.</p>
</blockquote>
<p>For more information on identifiers, see <a href="http://www.unicode.org/unicode/uni2book/ch05.pdf">Chapter
5, Implementation Guidelines</a>, and <a href="http://www.unicode.org/unicode/reports/tr15/#Programming%20Language%20Identifiers">UAX
#15, Annex 7</a>.</p>
<h2>Derived Extracted Properties</h2>
<p>The following files contain other properties of the UCD that are simply
separated out, and listed in range format. These files are provided purely as a
reformatting of existing data, with a certain exceptions listed below.</p>
<table border="1" width="100%" cellspacing="0" cellpadding="4">
<tr>
<th>".txt" Files</th>
<th valign="top">N/I</th>
<th>Definition and Generation</th>
</tr>
<tr>
<td valign="top">DerivedGeneralCategory</td>
<td align="center" valign="top">N</td>
<td>From UnicodeData.txt, field 2</td>
</tr>
<tr>
<td valign="top">DerivedCombiningClass</td>
<td align="center" valign="top">N</td>
<td>From UnicodeData.txt, field 3</td>
</tr>
<tr>
<td valign="top">DerivedBidiClass</td>
<td align="center" valign="top">N</td>
<td>From UnicodeData.txt, field 4</td>
</tr>
<tr>
<td valign="top">DerivedDecompositionType</td>
<td align="center" valign="top">*</td>
<td>From the <tag> in UnicodeData.txt, field 5. For characters with
canonical decomposition mappings (no tag), the value "canonical"
is used.
<p>* The value "canonical" is normative; the others are
informative.</p>
</td>
</tr>
<tr>
<td valign="top">DerivedNumericType</td>
<td align="center" valign="top">N</td>
<td>The property value is is based on the contents of UnicodeData.txt,
fields 6 through 8:
<div align="center">
<center>
<table border="1" cellspacing="0" cellpadding="4">
<tr>
<th width="50%">property value</th>
<th width="50%">non-empty fields</th>
</tr>
<tr>
<td width="50%">decimal</td>
<td width="50%">6, 7, & 8</td>
</tr>
<tr>
<td width="50%">digit</td>
<td width="50%">7 & 8</td>
</tr>
<tr>
<td width="50%">numeric</td>
<td width="50%">8</td>
</tr>
</table>
</center>
</div>
</td>
</tr>
<tr>
<td valign="top">DerivedNumericValues</td>
<td align="center" valign="top">N</td>
<td>From UnicodeData.txt, field 8</td>
</tr>
<tr>
<td valign="top">DerivedBinaryProperties</td>
<td align="center" valign="top">N</td>
<td>From UnicodeData.txt, field 9. See <a href="#Bidi_Note">Bidi Note</a>.</td>
</tr>
<tr>
<td valign="top">DerivedEastAsianWidth</td>
<td align="center" valign="top">I</td>
<td>From EastAsianWidth.txt, field 1</td>
</tr>
<tr>
<td valign="top">DerivedLineBreak</td>
<td align="center" valign="top">*</td>
<td>From LineBreak.txt, field 1.
<p>* Some values are normative; some are informative. See UTR #11: Line
Break Property for more information.</td>
</tr>
<tr>
<td valign="top">DerivedJoiningType</td>
<td align="center" valign="top">N</td>
<td>From ArabicShaping.txt, field 1</td>
</tr>
<tr>
<td valign="top">DerivedJoiningGroup</td>
<td align="center" valign="top">N</td>
<td>From ArabicShaping.txt, field 2</td>
</tr>
</table>
<blockquote>
<p><b><a name="Bidi_Note">Bidi Note</a>:</b> 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
BidiMirrored characters, where possible, to characters that normally have the
corresponding mirrored glyph.</p>
</blockquote>
<h2>Derived Normalization Properties</h2>
<p>The properties in DerivedNormalizationProperties.txt are useful in dealing
with normalization forms. In the following table, NF* refers to one of NFD, NFC,
NFKC, or NFKD.</p>
<table border="1" cellspacing="0" cellpadding="3" class="smallText">
<tr>
<th align="left">Property Value</th>
<th>N/I</th>
<th>Definition and Generation</th>
</tr>
<tr>
<th valign="top" align="left">FNC</th>
<th valign="top">N</th>
<td valign="top">Characters that require extra mappings for closure under
Case Folding plus Normalization Form KC. Characters marked with this
property have a third field with the mapping in it. Generated with the
following:<font face="Courier" size="2" color="#000000">
<pre>b = NFKC(Fold(a));
c = NFKC(Fold(b));
if (c != b) add mapping from a to c</pre>
</font></td>
</tr>
<tr>
<th valign="top" align="left">Comp_Ex</th>
<th valign="top">N</th>
<td valign="top">Characters that are excluded from composition: those
explicitly in CompositionExclusions.txt, plus:<br>
<i>(3) Singleton Decompositions</i><br>
<i>(4) Non-Starter Decompositions</i></td>
</tr>
<tr>
<th valign="top" align="left">NF*_NO</th>
<th valign="top">N</th>
<td valign="top">Characters that cannot ever occur in NF*. See <a href="#QuickCheck_Note">QuickCheck
Note</a>.</td>
</tr>
<tr>
<th valign="top" align="left">NF*_MAYBE</th>
<th valign="top">N</th>
<td valign="top">Characters that may occur in valid NF*, depending on the
context. See <a href="#QuickCheck_Note">QuickCheck Note</a>.</td>
</tr>
<tr>
<th valign="top" align="left">NF*_Expands</th>
<th valign="top">N</th>
<td valign="top">Characters that expand to more than one character in the
specified normalization form.</td>
</tr>
</table>
<blockquote>
<p><b><a name="QuickCheck_Note">QuickCheck Note</a>:</b> A previous version of
this data was in NormalizationQuickCheck.txt. For more information, see <a href="http://www.unicode.org/unicode/reports/tr15/#Annex8">UAX
#15 Annex 8</a>.)</p>
</blockquote>
<h2><i><a name="UCD_Terms">UCD Terms of Use</a></i></h2>
<h3><i>Disclaimer</i></h3>
<blockquote>
<p><i>The Unicode Character Database is provided as is by Unicode, Inc. No
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of information provided. If this file has been purchased on magnetic or
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exchange of defective media within 90 days of receipt.</i></p>
<p><i>This disclaimer is applicable for all other data files accompanying the
Unicode Character Database, some of which have been compiled by the Unicode
Consortium, and some of which have been supplied by other sources.</i></p>
</blockquote>
<h3><i>Limitations on Rights to Redistribute This Data</i></h3>
<blockquote>
<p><i>Recipient is granted the right to make copies in any form for internal
distribution and to freely use the information supplied in the creation of
products supporting the Unicode<sup>TM</sup> Standard. The files in the
Unicode Character Database can be redistributed to third parties or other
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</blockquote>
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