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Move script group definitions to intro so they're available to other parts of the draft
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‎css3-text/Overview.html‎

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@@ -220,6 +220,10 @@ <h2 class="no-num no-toc" id=contents>Table of Contents</h2>
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<ul class=toc>
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<li><a href="#intro"><span class=secno>1. </span> Introduction</a>
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<ul class=toc>
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<li><a href="#script-groups"><span class=secno>1.1. </span>Script
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Groups</a>
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</ul>
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<li><a href="#conformance"><span class=secno>2. </span> Conformance</a>
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<ul class=toc>
@@ -264,8 +268,8 @@ <h2 class="no-num no-toc" id=contents>Table of Contents</h2>
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and Word Boundaries</a>
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<ul class=toc>
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<li><a href="#line-break"><span class=secno>5.1. </span> Line Breaking
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Restrictions Strictness: the &lsquo;<code
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class=property>line-break</code>&rsquo; property</a>
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Strictness: the &lsquo;<code class=property>line-break</code>&rsquo;
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property</a>
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<li><a href="#word-break"><span class=secno>5.2. </span> Word Breaking
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Rules: the &lsquo;<code class=property>word-break</code>&rsquo;
@@ -452,6 +456,51 @@ <h2 id=intro><span class=secno>1. </span> Introduction</h2>
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<p>[document here]
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<h3 id=script-groups><span class=secno>1.1. </span>Script Groups</h3>
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<p>Typographic behavior varies somewhat by language, but varies drastically
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by writing system. For convenience, CSS3 Text defines the following script
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groups, which combine typographically-similar scripts together.
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<dl>
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<dt id=block-scripts><dfn id=block-scripts0>block scripts</dfn>
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<dd>CJK (including Hangul and half-width kana) and by extension all "wide"
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characters. (See <a href="#UAX11"
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rel=biblioentry>[UAX11]<!--{{!UAX11}}--></a>)
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<dt id=clustered-scripts><dfn id=clustered-scripts0>clustered
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scripts</dfn>
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<dd>South-East Asian scripts that have discrete units but do not use space
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between words (such as Thai, Lao, Khmer, Myanmar). This category also
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includes the Tibetan script.
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<dt id=discrete-scripts><dfn id=discrete-scripts0>discrete scripts</dfn>
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<dd>Scripts that use spaces or visible word-separating punctuation between
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words and have discrete, unconnected (in print) units within words, such
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as Latin, Greek, Ethiopic, Cyrillic, Hebrew.
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<dt id=cursive-scripts><dfn id=cursive-scripts0>cursive scripts</dfn>
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<dd>Arabic and similar cursive scripts.
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<dt id=connected-scripts><dfn id=connected-scripts0>connected
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scripts</dfn>
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<dd>Devanagari, Ogham, and other scripts that use spaces between words and
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baseline connectors within words. By extension this group also includes
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Gurmukhi, Tamil and any other Indic scripts whose typographic behavior is
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similar to Devanagari.
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</dl>
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<p class=issue>Provide an appendix using Unicode script names.
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<p class=note>These definitions are used primarily in describing <a
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href="#line-breaking">line-breaking</a> and <a
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href="#text-justify">justification</a> behavior.
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<h2 id=conformance><span class=secno>2. </span> Conformance</h2>
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<p>Conformance requirements are expressed with a combination of descriptive
@@ -1155,61 +1204,10 @@ <h2 id=line-breaking><span class=secno>5. </span> Line Breaking and Word
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scripts well. Additionally, some guidance should be provided on how to
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break or not break Southeast Asian in the absence of a dictionary.
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<h3 id=line-break><span class=secno>5.1. </span> Line Breaking Restrictions
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Strictness: the &lsquo;<a href="#line-break0"><code
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<h3 id=line-break><span class=secno>5.1. </span> Line Breaking Strictness:
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the &lsquo;<a href="#line-break0"><code
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class=property>line-break</code></a>&rsquo; property</h3>
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<p>This property specifies the strictness of line-breaking rules:
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particularly how line-breaking interacts with punctuation.
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<p>CSS distinguishes between three levels of strictness in the rules for
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implicit line breaking. The precise set of rules in effect for the
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&lsquo;<code class=css>strict</code>&rsquo; and &lsquo;<code
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class=css>loose</code>&rsquo; levels is up to the UA and should follow
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language conventions. However, this specification does recommend that:
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<ul>
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<li>Following breaks be forbidden in &lsquo;<code
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class=css>strict</code>&rsquo; line breaking and allowed in &lsquo;<code
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class=css>normal</code>&rsquo;:
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<ul>
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<li>breaks before Japanese small kana
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<li>breaks before the KATAKANA-HIRAGANA PROLONGED SOUND MARK (U+30FC)
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</ul>
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Additionally, if the language is known to be Chinese or Japanese, breaks
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before hyphens (U+2010, U+2013, U+301C, U+30A0) may be allowed in
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&lsquo;<code class=css>normal</code>&rsquo;.
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<li>Following breaks be forbidden in &lsquo;<code
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class=css>normal</code>&rsquo; and &lsquo;<code
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class=css>strict</code>&rsquo; line breaking and allowed in &lsquo;<code
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class=css>loose</code>&rsquo;:
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<ul>
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<li>breaks before iteration marks (U+3005, U+303B, U+309D, U+309E,
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U+30FD, U+30FE)
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<li>breaks between inseparatable characters (U+2014, U+2025, U+2026,
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U+3033, U+3034, U+3035)
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</ul>
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If the language is known to be Chinese or Japanese, then additionally the
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following breaks may be allowed in &lsquo;<code
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class=css>loose</code>&rsquo;:
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<ul>
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<li>breaks before middle dots (U+003A, U+003B, U+30FB, U+FF1A, U+FF1B,
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U+FF65)
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<li>breaks before dividing punctuation marks (U+0021, U+003F, U+203C,
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U+2047, U+2048, U+2049, U+FF01, U+FF1F)
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<li>breaks before postfixes (U+0025, U+00A2, U+00B0, U+2030, U+2032,
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U+2033, U+2103, U+FF05, U+FFE0)
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<li>breaks after prefixes (U+0024, U+00A3, U+00A5, U+20AC, U+2116,
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U+FF04, U+FFE1, U+FFE5)
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</ul>
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</ul>
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<table class=propdef>
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<tbody>
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<tr>
@@ -1253,8 +1251,9 @@ <h3 id=line-break><span class=secno>5.1. </span> Line Breaking Restrictions
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<td>specified value
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</table>
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<p>This property specifies what set of line breaking restrictions are in
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effect within the element. Values have the following meanings:
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<p>This property specifies the strictness of line-breaking rules applied
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within an element: particularly how line-breaking interacts with
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punctuation. Values have the following meanings:
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<dl>
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<dt><dfn id=auto title="line-break:auto"><code>auto</code></dfn>
@@ -1277,6 +1276,53 @@ <h3 id=line-break><span class=secno>5.1. </span> Line Breaking Restrictions
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<dd>Breaks text using the most stringent set of line-breaking rules.
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</dl>
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<p>CSS distinguishes between three levels of strictness in the rules for
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implicit line breaking. The precise set of rules in effect for each level
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is up to the UA and should follow language conventions. However, this
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specification does recommend that:
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<ul>
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<li>Following breaks be forbidden in &lsquo;<code
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class=css>strict</code>&rsquo; line breaking and allowed in &lsquo;<code
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class=css>normal</code>&rsquo;:
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<ul>
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<li>breaks before Japanese small kana
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<li>breaks before the KATAKANA-HIRAGANA PROLONGED SOUND MARK (U+30FC)
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</ul>
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Additionally, if the language is known to be Chinese or Japanese, breaks
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before hyphens (U+2010, U+2013, U+301C, U+30A0) may be allowed in
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&lsquo;<code class=css>normal</code>&rsquo;.
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<li>Following breaks be forbidden in &lsquo;<code
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class=css>normal</code>&rsquo; and &lsquo;<code
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class=css>strict</code>&rsquo; line breaking and allowed in &lsquo;<code
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class=css>loose</code>&rsquo;:
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<ul>
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<li>breaks before iteration marks (U+3005, U+303B, U+309D, U+309E,
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U+30FD, U+30FE)
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<li>breaks between inseparatable characters (U+2014, U+2025, U+2026,
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U+3033, U+3034, U+3035)
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</ul>
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If the language is known to be Chinese or Japanese, then additionally the
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following breaks may be allowed in &lsquo;<code
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class=css>loose</code>&rsquo;:
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<ul>
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<li>breaks before middle dots (U+003A, U+003B, U+30FB, U+FF1A, U+FF1B,
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U+FF65)
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<li>breaks before dividing punctuation marks (U+0021, U+003F, U+203C,
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U+2047, U+2048, U+2049, U+FF01, U+FF1F)
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<li>breaks before postfixes (U+0025, U+00A2, U+00B0, U+2030, U+2032,
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U+2033, U+2103, U+FF05, U+FFE0)
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<li>breaks after prefixes (U+0024, U+00A3, U+00A5, U+20AC, U+2116,
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U+FF04, U+FFE1, U+FFE5)
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</ul>
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</ul>
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<h3 id=word-break><span class=secno>5.2. </span> Word Breaking Rules: the
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&lsquo;<a href="#word-break0"><code
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class=property>word-break</code></a>&rsquo; property</h3>
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class=css>inter-ideograph</code>&rsquo; for CJK, or &lsquo;<code
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class=css>inter-word</code>&rsquo; for English. Another possibility is
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to use a justification method that is a universal compromise for all
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scripts, e.g. the &lsquo;<code class=css>distribute</code>&rsquo; method
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with discrete scripts dropped to second priority.</p>
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scripts, e.g. the &lsquo;<code class=css>inter-cluster</code>&rsquo;
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method with block scripts raised to first priority.</p>
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<dt><dfn id=none2 title="text-justify:none"><code>none</code></dfn>
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<dt><a name=kashida-prop></a><a name=text-kashida-space></a> <dfn
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id=kashida title="text-justify:kashida"><code>kashida</code></dfn>
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<dd>Justification primarily stretches Arabic and related scripts through
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the use of kashida or other calligraphic elongation.
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<dd>Justification primarily stretches <a href="#cursive-scripts">cursive
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scripts</a> through the use of kashida or other calligraphic elongation.
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</dl>
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<p>When justifying text, the user agent takes the remaining space between
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be followed when any justification method other than &lsquo;<code
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class=property>auto</code>&rsquo; is specified.
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<p>Justification affects different types of writing systems in different
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ways. For justification purposes, characters are grouped as follows:
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<dl>
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<dt id=block-scripts>block
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<dd>CJK (including Hangul and half-width kana) and by extension all "wide"
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characters. (See <a href="#UAX11"
2591-
rel=biblioentry>[UAX11]<!--{{!UAX11}}--></a>)
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<dt id=clustered-scripts>clustered
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<dd>South-East Asian scripts that have discrete units but do not use space
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between words (such as Thai, Lao, Khmer, Myanmar). This category also
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includes the Tibetan script.
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<dt id=discrete-scripts>discrete
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<dd>Scripts that use spaces or visible word-separating punctuation between
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words and have discrete, unconnected (in print) units within words, such
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as Latin, Greek, Ethiopic, Cyrillic, Hebrew.
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<dt id=cursive-scripts>cursive
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<dd>Arabic and similar cursive scripts
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<dt id=connected-scripts>connected
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<dd>Devanagari, Ogham, and other scripts that use spaces between words and
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baseline connectors within words. By extension this group also includes
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Gurmukhi, Tamil and any other Indic scripts whose typographic behavior is
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similar to Devanagari.
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</dl>
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<p>The UA may enable or break optional ligatures or use other font features
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such as alternate glyphs to help justify the text under any method. This
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behavior is not defined by CSS.
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<p id=expansion-opportunity>CSS defines <dfn
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id=expansion-opportunities>expansion opportunities</dfn> as points where
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the justification algorithm may alter spacing within the text. These
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lower priority expansion opportunities are adjusted. (Expansion and
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compression limits are given by the <a
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href="#letter-spacing">letter-spacing</a> and <a
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href="#word-spacing">word-spacing</a> properties.
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href="#word-spacing">word-spacing</a> properties.)
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<p>How any remaining space is distributed once all expansion opportunities
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reach their limits is up to the UA. If the inline contents of a line
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are given in the table below. Space must be distributed evenly among all
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types of expansion opportunities in a given prioritization group, but may
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vary within a line due to changes in the font or letter-spacing and
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word-spacing values. The different types of expansion opportunities are
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defined as follows:
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word-spacing values. Since justification behavior varies by writing
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system, expansion opportunities are organized by <a
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href="#script-groups">script group</a>. The different types of expansion
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opportunities are defined as follows:
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<dl>
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<dt>spaces
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<p class=note>The &lsquo;<code class=css>auto</code>&rsquo; column defined
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above is informative.
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<p>The UA may enable or break optional ligatures or use other font features
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such as alternate glyphs to help justify the text under any method. This
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behavior is not defined by CSS.
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<div class=example>
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<p>Japanese is one of the languages for which compression is preferred to
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expansion in applying justification.</p>
@@ -5957,12 +5971,27 @@ <h2 class=no-num id=index>Index</h2>
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<li>&lsquo;<code class=css>below right</code>&rsquo;, <a
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href="#below-right" title="''below right''"><strong>11.1.6.</strong></a>
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<li>block scripts, <a href="#block-scripts0" title="block
5975+
scripts"><strong>1.1.</strong></a>
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<li>clustered scripts, <a href="#clustered-scripts0" title="clustered
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scripts"><strong>1.1.</strong></a>
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<li>collapsible, <a href="#collapsible"
59615981
title=collapsible><strong>4.2.</strong></a>
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59635983
<li>&lsquo;<code class=css>column</code>&rsquo;, <a href="#column"
59645984
title="''column''"><strong>6.4.</strong></a>
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<li>connected scripts, <a href="#connected-scripts0" title="connected
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scripts"><strong>1.1.</strong></a>
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<li>cursive scripts, <a href="#cursive-scripts0" title="cursive
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scripts"><strong>1.1.</strong></a>
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<li>discrete scripts, <a href="#discrete-scripts0" title="discrete
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scripts"><strong>1.1.</strong></a>
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59665995
<li><a href="#each-line"><code>each-line</code></a>, <a href="#each-line"
59675996
title=each-line><strong>10.1.</strong></a>
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