<pre class='metadata'>

Title: CSS Text Module Level 4

Shortname: css-text

Level: 4

Status: ED

Work Status: Exploring

Group: csswg

ED: https://drafts.csswg.org/css-text-4/

TR: https://www.w3.org/TR/css-text-4/

Previous Version: https://www.w3.org/TR/2024/WD-css-text-4-20240529/

Editor: Elika J. Etemad / fantasai, Apple, http://fantasai.inkedblade.net/contact, w3cid 35400

Editor: Koji Ishii, Invited Expert, [email protected], w3cid 45369

Editor: Alan Stearns, Adobe Systems, [email protected], w3cid 46659

Editor: Florian Rivoal, Invited Expert, https://florian.rivoal.net, w3cid 43241

Abstract: This CSS module defines properties for text manipulation and specifies their processing model. It covers line breaking, justification and alignment, white space handling, and text transformation.

Ignored Vars: letter-spacing

WPT Path Prefix: /css/css-text/

</pre>

<pre class=link-defaults>

spec:css-display-3; type:property; text:display

spec:css-fonts-4; type:property; text:font-feature-settings

spec:selectors-4; type:selector; text::lang()

spec:css2; type:dfn; text:document language

spec:css-ruby-1; type:dfn; text:ruby

spec:selectors-4; type:dfn; text:selector

</pre>

<pre class=biblio>

{

"L2-22-080R": {

"authors": [

"Norbert Lindenberg",

"Elika Etemad",

"Vaishnavi Murthy Yerkadithaya"

],

"href": "https://www.unicode.org/L2/L2022/22080r-line-break-ortho-bnd.pdf",

"title": "Line breaking at orthographic syllable boundaries",

"status": "Proposal",

"publisher": "Unicode Consortium"

}

}

</pre>

<style type="text/css">

img { vertical-align: middle; }

span[lang] {

font-size: 125%;

line-height: 1;

vertical-align: middle;

}

/* Bidi & spaces example */

.egbidiwsaA,.egbidiwsbB,.egbidiwsaB,.egbidiwsbC {

white-space: pre;

font-size: 80%;

font-family: monospace;

vertical-align: 2px;

margin: 1px;

}

.egbidiwsaA {

background: lime;

padding: 2px;

}

.egbidiwsbB { border: 2px solid blue; }

.egbidiwsaB {

background: yellow;

border: 2px dotted white;

}

.egbidiwsbC { border:2px dotted red; }

.hyphens-ex {

border: thin solid black;

display: inline-block;

padding: 4pt;

}

/* Start Letter-spacing Tutorial */

.ls-ex {

font-size: 200%;

margin-left: 1em;

margin-right: 1em;

}

.ls-fixed-width {

width: 10em;

}

.color-box { background: rgb(224, 203, 82); }

.bad { color: red; }

.good { color: green; }

/* End Letter-spacing Tutorial */

.char { border: 1px dotted gray; }

.quarter { font-size: 25%; }

tt[lang="ja"] { font-family: "MS Gothic", "Osaka", monospace; }

div.figure table {

margin: auto;

}

.feedback {

background: #FFEECC;

border-color: orange;

}

.feedback:before {

content: "Info Needed";

color: #FF8800;

}

.data .no { color: red; }

.data .ok { color: green; }

.data th em {

display: block;

font-size: smaller;

font-weight: normal;

font-style: italic;

}

.no-quote.no-quote::before,

.no-quote.no-quote::after {

content: none;

}

/* Displaying the output of text layout,

particularly when line-breaking is being invoked,

and thus having a visible width is good. */

pre.output {

margin: 1em;

border: solid thin silver;

padding: 0.25em;

display: table;

}

</style>

<h2 id="intro">

Introduction</h2>

<wpt title="

The test coverage information in this specification

covers <a href='https://github.com/web-platform-tests/wpt/tree/master/css/css-text/'>wpt/css/css-text/</a> and subdirectories,

as well as those tests in <a href='https://github.com/web-platform-tests/wpt/tree/master/css/CSS2/'>wpt/css/CSS2/</a> and subdirectories

that relate to this specification."></wpt>

This module describes the typesetting controls of CSS;

that is, the features of CSS that control the translation of

source text to formatted, line-wrapped text.

Various CSS properties provide control over

[[#transforming|case transformation]],

[[#white-space-processing|white space collapsing]],

[[#white-space-property|text wrapping]],

[[#line-breaking|line breaking rules]]

and [[#hyphenation|hyphenation]],

[[#justification|alignment and justification]],

[[#spacing|spacing]],

and [[#edge-effects|indentation]].

See [[#changes-L3]] for additions since [[CSS-TEXT-3|Level 3]].

<div class="note">

Note: Font selection is covered in the <a href="https://www.w3.org/TR/css-fonts-3/"><cite>CSS Fonts Module</cite></a>.

[[CSS-FONTS-3]]

<span id="decoration"></span>

<span id="text-decoration"></span>

<span id="line-decoration"></span>

<span id="text-decoration-line"></span>

<span id="text-decoration-color"></span>

<span id="text-decoration-style"></span>

<span id="text-decoration-skip"></span>

<span id="text-underline-position"></span>

<span id="emphasis-marks"></span>

<span id="text-emphasis-style"></span>

<span id="text-emphasis-color"></span>

<span id="text-emphasis"></span>

<span id="text-emphasis-position"></span>

<span id="text-shadow"></span>

Features for decorating text,

such as [[css-text-decor-3#line-decoration|underlines]],

[[css-text-decor-3#emphasis-marks|emphasis marks]],

and [[css-text-decor-3#text-shadow-property|shadows]],

(previously part of this module)

are covered in the

<a href="https://www.w3.org/TR/css-text-decor-3/"><cite>CSS Text Decoration Module</cite></a>.

[[CSS-TEXT-DECOR-3]]

[[css-writing-modes-4#text-direction|Bidirectional]] and

[[css-writing-modes-4#vertical-intro|vertical]] text

are addressed in the

<a href="https://www.w3.org/TR/css-writing-modes-4/"><cite>CSS Writing Modes Module</cite></a>.

[[CSS-WRITING-MODES-4]].

</div>

Further information about the typesetting requirements

of various languages and writing systems around the world

can be found in the <a href="https://www.w3.org/International/core/">Internationalization Working Group</a>’s

<a href="https://www.w3.org/TR/typography/"><cite>Language Enablement Index</cite></a>.

[[TYPOGRAPHY]]

<wpt title="

The following tests are crash tests

that relate to general usage

of the features described in this specification

but are not tied to any particular normative statement.">

removing-collapsible-crash.html

removing-collapsible-spaces-before-float-crash.html

crashtests/line-break-float-crash.html

crashtests/trailing-space-with-cr-crash.html

ellisize-rtl-text-crash.html

altering-dom-crash.html

whitespace-followed-by-cham-symbol-crash.html

white-space/append-whitespace-only-node-crash-001.html

crashtests/rendering-rtl-bidi-override-crash.html

crashtests/rendering-table-caption-with-list-item-and-svg-crash.html

crashtests/rendering-table-caption-with-negative-margins-crash.html

crashtests/white-space-pre-wrap-chash.html

crashtests/word-spacing-large-value.html

crashtests/eol-spaces-bidi-min-content-crash.html

crashtests/overflow-wrap-anywhere-crash.html

crashtests/text-indent-each-line-crash.html

overflow-wrap/crashtests/overflow-wrap-leading-floats-crash.html

text-autospace/crashtests/text-autospace-shape-cache-crash.html

text-indent/text-indent-ruby-crash.html

hyphens/hyphens-auto-wordbreak-breakall-crash.html

</wpt>

<h3 id="placement">

Module Interactions</h3>

<wpt title="Tests not needed for this section."></wpt>

This module, together with the <cite><a href="https://www.w3.org/TR/css-text-decor-3/">CSS Text Decoration Module</a></cite>,

replaces and extends the text-level features defined in

<a href="https://www.w3.org/TR/CSS2/text.html"><cite>Cascading Style Sheets Level 2</cite> chapter 16</a>.

[[CSS-TEXT-DECOR-3]]

[[!CSS2]]

In addition to the terms defined below,

other terminology and concepts used in this specification are defined

in <a href="https://www.w3.org/TR/CSS2/"><cite>Cascading Style Sheets Level 2</cite></a>

and the <a href="https://www.w3.org/TR/css-writing-modes-4/"><cite>CSS Writing Modes Module</cite></a>.

[[!CSS2]] and [[!CSS-WRITING-MODES-4]].

<h3 id="values">

Value Definitions</h3>

<wpt title="

Tests not really needed for this section;

could possibly test that css-wide keywords apply to every property."></wpt>

This specification follows the [[CSS2/about#property-defs|CSS property definition conventions]] from [[!CSS2]]

using the [[css-values-3#value-defs|value definition syntax]] from [[!CSS-VALUES-3]].

Value types not defined in this specification are defined in CSS Values &amp; Units [[!CSS-VALUES-3]].

Combination with other CSS modules may expand the definitions of these value types.

In addition to the property-specific values listed in their definitions,

all properties defined in this specification

also accept the [=CSS-wide keywords=] as their property value.

For readability they have not been repeated explicitly.

<h3 id="languages">

Languages and Typesetting</h3>

<wpt title="

Tests not needed for this section:

these are definitions,

they get tested through their application,

not by themselves."></wpt>

<p class="advisement">

<strong>Authors should accurately language-tag their content

for the best typographic behavior.</strong>

Many typographic effects vary by linguistic context.

Language and writing system conventions can affect

line breaking, hyphenation, justification, glyph selection,

and many other typographic effects.

<strong>In CSS, language-specific typographic tailorings

are only applied when the [=content language=] is known (declared).</strong>

Therefore,

higher quality typography requires authors to communicate to the UA

the correct linguistic context of the text in the document.

The <dfn export>content language</dfn> of an element is the (human) language

the element is declared to be in, according to the rules of the

[=document language=].

Note that it is possible for the [=content language=] of an element

to be unknown--

e.g. untagged content,

or content in a [=document language=] that does not have a language-tagging facility,

is considered to have an unknown [=content language=].

Note: Authors can declare the [=content language=]

using the global <code>lang</code> attribute in HTML

or the universal <code>xml:lang</code> attribute in XML.

See the <a spec=html lt=language for=Node>rules for determining the content language of an HTML element</a>

in <cite>HTML</cite>,

and the [[XML#sec-lang-tag|rules for determining the content language of an XML element]] in <cite>XML 1.0</cite>.

[[HTML]]

[[XML10]]

The [=content language=] an element is declared to be in

also identifies the specific written form of that language used in that element,

known as the <dfn export local-lt="writing system">content writing system</dfn>.

Depending on the [=document language=]’s facilities for identifying the [=content language=],

this information can be explicit or implied.

See the normative [[#script-tagging]].

Note: Some languages have more than one writing system tradition;

in other cases a language can be transliterated into a foreign writing system.

Authors should [[#script-tagging|subtag]] such cases

so that the UA can adapt appropriately.

<div class=example>

For example, Korean (<code>ko</code>) can be written in

Hangul (<code>-Hang</code>),

Hanja (<code>-Hani</code>),

or a combination (<code>-Kore</code>).

Historical documents written solely in Hanja

do not use word spaces and

are formatted more like modern Chinese than modern Korean.

In other words, for typographic purposes <code>ko-Hani</code>

behaves more like <code>zh-Hant</code>

than <code>ko</code> (<code>ko-Kore</code>).

As another example Japanese (<code>ja</code>) is typically written

in a combination (<code>-Japn</code>) of Hiragana (<code>-Hira</code>),

Katakana (<code>-Kana</code>), and Kanji (<code>-Hani</code>).

However, it can also be “romanized” into Latin (<code>-Latn</code>)

for special purposes like language-learning textbooks,

in which case it should be formatted more like English than Japanese.

As a third example contemporary Mongolian is written in two scripts:

Cyrillic (<code>-Cyrl</code>, officially used in Mongolia)

and Mongolian (<code>-Mong</code>, more common in Inner Mongolia, part of China).

These have very different formatting requirements,

with Cyrillic behaving similar to Latin and Greek,

and Mongolian deriving from both Arabic and Chinese writing conventions.

</div>

<h3 id="characters">

Characters and Letters</h3>

<wpt title="

For the most part, tests not really needed for this section:

these are definitions,

they get tested through their applications,

by themselves.

The few testable assertions that are made have coverage.

Possible additions:

* turning the content of example 1 into tests (first, check that it’s not already done)."></wpt>

The basic unit of typesetting is the <dfn export>character</dfn>.

However, because writing systems are not always as simple as the basic English alphabet,

what a [=character=] actually is depends on the context in which the term is used.

For example, in Hangul (the Korean writing system),

each square representation of a syllable

(e.g. <span lang=ko-hang title="Hangul syllable HAN">한</span>=<span lang=ko-Latn>Han</span>)

can be considered a <a>character</a>.

However, the square symbol is really composed of multiple letters each representing a phoneme

(e.g. <span lang=ko-hang title="Hangul letter HIEUH">ㅎ</span>=<span lang=ko-Latn>h</span>,

<span lang=ko-hang title="Hangul letter HIEUH">ㅏ</span>=<span lang=ko-Latn>a</span>,

<span lang=ko-hang title="Hangul letter HIEUH">ㄴ</span>=<span lang=ko-Latn>n</span>)

and these also could each be considered a <a>character</a>.

A basic unit of computer text encoding, for any given encoding,

is also called a [=character=],

and depending on the encoding,

a single encoding [=character=] might correspond

to the entire pre-composed syllabic [=character=] (e.g. <span lang=ko-hang title="Hangul syllable HAN">한</span>),

to the individual phonemic [=character=] (e.g. <span lang=ko-hang title="Hangul letter HIEUH">ㅎ</span>),

or to smaller units such as

a base letterform (e.g. <span lang=ko-hang title="Hangul letter IEUNG">ㅇ</span>)

and any combining marks that vary it (e.g. extra strokes that represent aspiration).

In turn, a single encoding [=character=] can be represented in the data stream as one or more bytes;

and in programming environments one byte is sometimes also called a [=character=].

Therefore the term [=character=] is fairly ambiguous where technical precision is required.

For text layout, we will refer to the <dfn export lt="typographic character unit|typographic character">typographic character unit</dfn>

as the basic unit of text.

Even within the realm of text layout,

the relevant [=character=] unit depends on the operation.

For example, line-breaking and letter-spacing will segment

a sequence of Thai characters that include U+0E33 &nbsp;ำ THAI CHARACTER SARA AM differently;

or the behavior of a conjunct consonant in a script such as Devanagari

may depend on the font in use.

So the [=typographic character=] represents a unit of the writing system--

such as a Latin alphabetic letter (including its diacritics),

Hangul syllable,

Chinese ideographic character,

Myanmar syllable cluster--

that is indivisible with respect to a particular typographic operation

(line-breaking, first-letter effects, tracking, justification, vertical arrangement, etc.).

<wpt>

word-break/word-break-break-all-007.html

word-break/word-break-break-all-008.html

</wpt>

<a href="http://www.unicode.org/reports/tr29/"><cite>Unicode Standard Annex #29: Text Segmentation</cite></a>

defines a unit called the <dfn>grapheme cluster</dfn>

which approximates the [=typographic character=].

[[!UAX29]]

A UA must use the <em>extended grapheme cluster</em>

(not <em>legacy grapheme cluster</em>), as defined in <cite>UAX29</cite>,

as the basis for its [=typographic character unit=].

However, the UA should tailor the definitions

as required by typographic tradition

since the default rules are not always appropriate or ideal--

and is expected to tailor them differently

depending on the operation as needed.

<wpt>

line-breaking/line-breaking-013.html

line-breaking/line-breaking-014.html

</wpt>

Note: The rules for such tailorings are out of scope for CSS.

<div class="example">

The following are some examples of [=typographic character unit=] tailorings

required by standard typesetting practice:

<ul>

<li>

In some scripts such as Myanmar or Devanagari,

the [=typographic character unit=] for both justification and line-breaking

is an entire syllable,

which can include more than one Unicode [=grapheme cluster=].

[[!UAX29]]

<li>

In other scripts such as Thai or Lao,

even though for line-breaking the [=typographic character=]

matches Unicode’s default [=grapheme clusters=],

for letter-spacing the relevant unit

is <em>less</em> than a Unicode [=grapheme cluster=],

and may require decomposition or other substitutions

before spacing can be inserted.

[[!UAX29]]

For instance,

to properly letter-space the Thai word คำ (U+0E04 + U+0E33),

the U+0E33 needs to be decomposed into U+0E4D + U+0E32,

and then the extra letter-space inserted before the U+0E32: คํ า.

A slightly more complex example is น้ำ (U+0E19 + U+0E49 + U+0E33).

In this case, normal Thai shaping will first decompose the U+0E33 into U+0E4D + U+0E32

and then swap the U+0E4D with the U+0E49, giving U+0E19 + U+0E4D + U+0E49 + U+0E32.

As before the extra letter-space is then inserted before the U+0E32: นํ้ า.

<li>

Vertical typesetting can also require tailoring.

For example, when typesetting ''text-orientation/upright'' text,

Tibetan tsek and shad marks are kept with the preceding grapheme cluster,

rather than treated as an independent [=typographic character unit=].

[[!CSS-WRITING-MODES-4]]

</ul>

</div>

A <dfn export>typographic letter unit</dfn>

(or <dfn noexport>letter</dfn> for the purpose of this specification)

is a [=typographic character unit=] belonging to one of the Letter or Number

[=general categories=].

See [[#character-properties]]

for how to determine the Unicode properties of a [=typographic character unit=].

The rendering characteristics of a [=typographic character unit=] divided

by an element boundary is undefined.

Ideally each component should be rendered

according to the formatting requirements of its respective element’s properties

while maintaining correct shaping and positioning

of the [=typographic character unit=] as a whole.

However, depending on the nature of the formatting differences between its parts

and the capabilities of the font technology in use,

this is not always possible.

Therefore such a [=typographic character unit=]

may be rendered as belonging to either side of the boundary,

or as some approximation of belonging to both.

Authors are forewarned that dividing [=grapheme clusters=]

or ligatures

by element boundaries may give inconsistent or undesired results.

<h3 id="text-encoding">

Text Processing</h3>

<wpt title="

This section has adequate coverage.

Exhaustive coverage unrealistic,

since this section is effectively a dependency on all of Unicode.

Some tests nonetheless provided for key functionality

(such as the effect of certain control characters on Arabic shaping)."></wpt>

CSS is built on <a href="https://www.unicode.org/versions/latest/">Unicode</a>.

[[UNICODE]]

UAs that support Unicode must adhere to all normative requirements

of the Unicode Core Standard,

except where explicitly overridden by CSS.

UAs implemented on the basis of a non-Unicode text encoding model are still

expected to fulfill the same text handling requirements

by assuming an appropriate mapping and analogous behavior.

<wpt>

text-encoding/shaping-join-001.html

text-encoding/shaping-join-002.html

text-encoding/shaping-join-003.html

text-encoding/shaping-no-join-001.html

text-encoding/shaping-no-join-002.html

text-encoding/shaping-no-join-003.html

text-encoding/shaping-tatweel-001.html

text-encoding/shaping-tatweel-002.html

text-encoding/shaping-tatweel-003.html

shaping/shaping-arabic-diacritics-001.html

shaping/shaping-arabic-diacritics-002.html

white-space/full-width-leading-spaces-005.html

white-space/object-replacement-1.html

white-space/object-replacement-2.html

white-space/white-space-vs-joiners-001.html

white-space/white-space-vs-joiners-002.html

</wpt>

For the purpose of determining adjacency for text processing

(such as white space processing, text transformation, line-breaking, etc.),

and thus in general within this specification,

intervening [=inline box=] boundaries and [=out-of-flow=] elements

must be ignored.

With respect to text shaping, however, see [[#boundary-shaping]].

<wpt>

line-breaking/line-breaking-002.html

line-breaking/line-breaking-003.html

line-breaking/line-breaking-004.html

line-breaking/line-breaking-005.html

line-breaking/line-breaking-006.html

line-breaking/line-breaking-007.html

line-breaking/line-breaking-008.html

<!-- to be moved/removed together with the segment break transformation text

white-space/seg-break-transformation-018.html

white-space/seg-break-transformation-019.html

-->

word-break/word-break-min-content-002.html

word-break/word-break-min-content-003.html

word-break/word-break-min-content-004.html

word-break/word-break-min-content-005.html

overflow-wrap/overflow-wrap-anywhere-010.html

</wpt>

<wpt pathprefix="/css/CSS2/text/">

white-space-processing-048.xht

white-space-processing-049.xht

</wpt>

<h2 id="transforming">

Transforming Text</h2>

<h3 id="text-transform-property" oldids="text-transform,caps-prop">

Case Transforms: the 'text-transform' property</h3>

<wpt title="

This section has good test coverage overall,

and very good i18n coverage in particular.

Missing tests:

* no test of Animation type.

* Applies to text

Possible additions:

* An automated test for plain text copy&amp;paste not applying transforms. Not clear such an <em>automated</em> test is possible, but it would be nice to have one if it were."></wpt>

<pre class="propdef">

Name: text-transform

Value: none | [capitalize | uppercase | lowercase ] || full-width || full-size-kana | math-auto

Initial: none

Applies to: text

Inherited: yes

Canonical order: n/a

Computed value: specified keyword

Animation type: discrete

</pre>

<wpt>

inheritance.html

parsing/text-transform-valid.html

parsing/text-transform-invalid.html

parsing/text-transform-computed.html

text-transform/text-transform-multiple-001.html

</wpt>

<wpt pathprefix="/css/CSS2/css1">

c545-txttrans-000.xht

</wpt>

<wpt pathprefix="/css/CSS2/text/">

text-transform-005.xht

text-transform-applies-to-001.xht

text-transform-applies-to-002.xht

text-transform-applies-to-003.xht

text-transform-applies-to-005.xht

text-transform-applies-to-006.xht

text-transform-applies-to-007.xht

text-transform-applies-to-008.xht

text-transform-applies-to-009.xht

text-transform-applies-to-010.xht

text-transform-applies-to-011.xht

text-transform-applies-to-012.xht

text-transform-applies-to-013.xht

text-transform-applies-to-014.xht

text-transform-applies-to-015.xht

</wpt>

This property transforms text for styling purposes.

It has no effect on the underlying content,

and must not affect the content of a plain text copy &amp; paste operation.

<wpt>

text-transform/text-transform-upperlower-105.html

</wpt>

Advisement: Authors must not rely on 'text-transform' for semantic purposes;

rather the correct casing and semantics should be encoded

in the source document text and markup.

<wpt>

text-transform/text-transform-copy-paste-001-manual.html

</wpt>

Values have the following meanings:

<dl dfn-for=text-transform dfn-type=value>

<dt><dfn>none</dfn>

<dd>

No effects.

<wpt>

text-transform/text-transform-none-001.xht

</wpt>

<wpt pathprefix="/css/CSS2/text/">

text-transform-004.xht

</wpt>

<dt><dfn>capitalize</dfn>

<dd>

Puts the first [=typographic letter unit=] of each word, if lowercase, in titlecase;

other characters are unaffected.

<wpt>

text-transform/text-transform-capitalize-001.html

text-transform/text-transform-capitalize-003.html

text-transform/text-transform-capitalize-005.html

text-transform/text-transform-capitalize-007.html

text-transform/text-transform-capitalize-009.html

text-transform/text-transform-capitalize-010.html

text-transform/text-transform-capitalize-011.html

text-transform/text-transform-capitalize-014.html

text-transform/text-transform-capitalize-016.html

text-transform/text-transform-capitalize-018.html

text-transform/text-transform-capitalize-020.html

text-transform/text-transform-capitalize-022.html

text-transform/text-transform-capitalize-024.html

text-transform/text-transform-capitalize-026.html

text-transform/text-transform-capitalize-028.html

text-transform/text-transform-capitalize-030.html

text-transform/text-transform-capitalize-031.html

text-transform/text-transform-capitalize-032.xht

text-transform/text-transform-capitalize-034.html

text-transform/text-transform-capitalize-035.html

</wpt>

<wpt pathprefix="/css/CSS2/text/">

text-transform-001.xht

text-transform-cap-001.xht

text-transform-cap-002.xht

text-transform-cap-003.xht

</wpt>

<dt><dfn>uppercase</dfn>

<dd>

Puts all [=letters=] in uppercase.

<wpt>

text-transform/text-transform-uppercase-101.xht

text-transform/text-transform-upperlower-001.html

text-transform/text-transform-upperlower-003.html

text-transform/text-transform-upperlower-005.html

text-transform/text-transform-upperlower-007.html

text-transform/text-transform-upperlower-009.html

text-transform/text-transform-upperlower-011.html

text-transform/text-transform-upperlower-015.html

text-transform/text-transform-upperlower-017.html

text-transform/text-transform-upperlower-019.html

text-transform/text-transform-upperlower-021.html

text-transform/text-transform-upperlower-023.html

text-transform/text-transform-upperlower-025.html

text-transform/text-transform-upperlower-027.html

text-transform/text-transform-upperlower-029.html

text-transform/text-transform-upperlower-031.html

text-transform/text-transform-upperlower-044.html

text-transform/text-transform-upperlower-101.html

text-transform/text-transform-upperlower-103.html

text-transform/text-transform-upperlower-106.html

text-transform/text-transform-uppercase-dynamic.html

</wpt>

<wpt pathprefix="/css/CSS2/text/">

text-transform-003.xht

text-transform-bicameral-001.xht

text-transform-bicameral-003.xht

text-transform-bicameral-005.xht

text-transform-bicameral-007.xht

text-transform-bicameral-009.xht

text-transform-bicameral-011.xht

text-transform-bicameral-013.xht

text-transform-bicameral-015.xht

text-transform-bicameral-017.xht

text-transform-bicameral-019.xht

text-transform-bicameral-021.xht

text-transform-unicase-001.xht

text-transform-uppercase-001.xht

text-transform-uppercase-002.xht

</wpt>

<dt><dfn>lowercase</dfn>

<dd>

Puts all [=letters=] in lowercase.

<wpt>

text-transform/text-transform-lowercase-101.xht

text-transform/text-transform-lowercase-102.xht

text-transform/text-transform-upperlower-002.html

text-transform/text-transform-upperlower-004.html

text-transform/text-transform-upperlower-006.html

text-transform/text-transform-upperlower-008.html

text-transform/text-transform-upperlower-010.html

text-transform/text-transform-upperlower-012.html

text-transform/text-transform-upperlower-014.html

text-transform/text-transform-upperlower-016.html

text-transform/text-transform-upperlower-018.html

text-transform/text-transform-upperlower-020.html

text-transform/text-transform-upperlower-022.html

text-transform/text-transform-upperlower-024.html

text-transform/text-transform-upperlower-026.html

text-transform/text-transform-upperlower-028.html

text-transform/text-transform-upperlower-030.html

text-transform/text-transform-upperlower-102.html

text-transform/text-transform-upperlower-104.html

</wpt>

<wpt pathprefix="/css/CSS2/text/">

text-transform-002.xht

text-transform-bicameral-002.xht

text-transform-bicameral-004.xht

text-transform-bicameral-006.xht

text-transform-bicameral-008.xht

text-transform-bicameral-010.xht

text-transform-bicameral-012.xht

text-transform-bicameral-014.xht

text-transform-bicameral-016.xht

text-transform-bicameral-018.xht

text-transform-bicameral-020.xht

text-transform-bicameral-022.xht

text-transform-lowercase-001.xht

</wpt>

<dt><dfn>full-width</dfn>

<dd>

Puts all [=typographic character units=] in [=full-width=] form.

If a character does not have a corresponding [=full-width=] form,

it is left as is.

This value is typically used to typeset Latin letters and digits

as if they were ideographic characters.

<wpt>

text-transform/text-transform-fullwidth-001.xht

text-transform/text-transform-fullwidth-002.xht

text-transform/text-transform-fullwidth-004.xht

text-transform/text-transform-fullwidth-005.xht

</wpt>

<dt><dfn>full-size-kana</dfn>

<dd>

Converts all [=small Kana=] characters to the equivalent [=full-size Kana=].

This value is typically used for ruby annotation text,

where authors may want all small Kana to be drawn as large Kana

to compensate for legibility issues at the small font sizes typically used in ruby.

<wpt>

text-transform/text-transform-full-size-kana-001.html

text-transform/text-transform-full-size-kana-002.html

text-transform/text-transform-full-size-kana-003.html

text-transform/text-transform-full-size-kana-004.html

text-transform/text-transform-full-size-kana-005.html

text-transform/text-transform-full-size-kana-006.html

text-transform/text-transform-full-size-kana-007.html

text-transform/text-transform-full-size-kana-008.html

</wpt>

<dt><dfn>math-auto</dfn>

<dd>

See [[mathml-core#math-auto-transform]].

<wpt>

text-transform/math/text-transform-math-auto-001.html

text-transform/math/text-transform-math-auto-002.html

text-transform/math/text-transform-math-auto-003.html

</wpt>

</dl>

<div class="example">

The following example converts the ASCII characters

used in abbreviations in Japanese text to their full-width variants

so that they lay out and line break like ideographs:

<pre highlight=css>abbr:lang(ja) { text-transform: full-width; }</pre>

</div>

Note: The purpose of 'text-transform' is

to allow for presentational casing transformations

without affecting the semantics of the document.

Note in particular that 'text-transform' casing operations are lossy,

and can distort the meaning of a text.

While accessibility interfaces may wish to convey

the apparent casing of the rendered text to the user,

the transformed text cannot be relied on to accurately represent

the underlying meaning of the document.

<div class="example">

In this example,

the first line of text is capitalized as a visual effect.

<pre highlight=css>

section > p:first-of-type::first-line {

text-transform: uppercase;

}

</pre>

This effect cannot be written into the source document

because the position of the line break depends on layout.

But also, the capitalization is not reflecting a semantic distinction

and is not intended to affect the paragraph’s reading;

therefore it belongs in the presentation layer.

</div>

<div class="example">

In this example,

the [=ruby=] annotations,

which are half the size of the main paragraph text,

are transformed to use regular-size kana

in place of [=small kana=].

<pre highlight=css>

rt { font-size: 50%; text-transform: full-size-kana; }

:is(h1, h2, h3, h4) rt { text-transform: none; /* unset for large text*/ }

</pre>

Note that while this makes such letters easier to see at small type sizes,

the transformation distorts the text:

the reader needs to mentally substitute [=small kana=]

in the appropriate places--

not unlike reading a Latin inscription

where all “U”s look like “V”s.

For example, if ''text-transform: full-size-kana'' were applied to the following source,

the annotation would read “じゆう” (jiyū), which means “liberty”,

instead of “じゅう” (jū), which means “ten”,

the correct reading and meaning for the annotated “十”.

<xmp highlight=html>

<ruby>十<rt>じゅう</ruby>

</xmp>

</div>

<h4 id="text-transform-mapping">

Mapping Rules</h4>

<wpt title="

This section has adequate test coverage."></wpt>

For ''capitalize'', what constitutes a “word“ is UA-dependent;

[[!UAX29]] is suggested (but not required)

for determining such word boundaries.

Out-of-flow elements and inline element boundaries

must not introduce a 'text-transform' word boundary

and must be ignored when determining such word boundaries.

<wpt>

text-transform/text-transform-capitalize-033.html

text-transform/text-transform-capitalize-034.html

text-transform/text-transform-capitalize-035.html

</wpt>

Note: Authors cannot depend on ''capitalize'' to follow

language-specific titlecasing conventions

(such as skipping articles in English).

The UA must use the full case mappings for Unicode characters,

including any conditional casing rules,

as defined in the <cite>Default Case Algorithms</cite> section of <cite>The Unicode Standard</cite>.

[[!UNICODE]]

If (and only if) the [=content language=] of the element is,

according to the rules of the [=document language=],

known,

then any appropriate language-specific rules must be applied as well.

These minimally include,

but are not limited to,

the language-specific rules in Unicode’s

<a href="http://www.unicode.org/Public/UNIDATA/SpecialCasing.txt">SpecialCasing.txt</a>.

<wpt>

writing-system/writing-system-text-transform-001.html

text-transform/text-transform-tailoring-001.html

text-transform/text-transform-tailoring-002.html

text-transform/text-transform-tailoring-002a.html

text-transform/text-transform-tailoring-003.html

text-transform/text-transform-tailoring-004.html

text-transform/text-transform-tailoring-005.html

text-transform/text-transform-upperlower-032.html

text-transform/text-transform-upperlower-033.html

text-transform/text-transform-upperlower-034.html

text-transform/text-transform-upperlower-035.html

text-transform/text-transform-upperlower-038.html

text-transform/text-transform-upperlower-039.html

text-transform/text-transform-upperlower-040.html

text-transform/text-transform-upperlower-041.html

text-transform/text-transform-upperlower-042.html

text-transform/text-transform-upperlower-043.html

</wpt>

<div class="example">

For example, in Turkish there are two &ldquo;i&rdquo;s,

one with a dot--

&ldquo;İ&rdquo; and &ldquo;i&rdquo;--

and one without--

&ldquo;I&rdquo; and &ldquo;ı&rdquo;.

Thus the usual case mappings between &ldquo;I&rdquo; and &ldquo;i&rdquo;

are replaced with a different set of mappings

to their respective dotless/dotted counterparts,

which do not exist in English.

This mapping must only take effect

if the [=content language=] is Turkish

written in its modern Latin-based [=writing system=]

(or another Turkic language that uses Turkish casing rules);

in other languages,

the usual mapping of &ldquo;I&rdquo; and &ldquo;i&rdquo; is required.

This rule is thus conditionally defined in Unicode’s SpecialCasing.txt file.

</div>

<wpt pathprefix="/css/CSS2/text/">

text-transform-bicameral-005.xht

text-transform-bicameral-006.xht

</wpt>

The definition of <dfn>full-width</dfn> and <dfn noexport>half-width</dfn> forms

can be found in <a href="https://www.unicode.org/reports/tr11/"><cite></cite>Unicode Standard Annex #11: East Asian Width</a>.

[[!UAX11]]

The mapping to [=full-width=] form is defined

by taking code points with the <code>&lt;wide&gt;</code>

or the <code>&lt;narrow&gt;</code> tag

in their <code>Decomposition_Mapping</code>

in <a href="https://www.unicode.org/reports/tr44/"><cite></cite>Unicode Standard Annex #44: Unicode Character Database</a>.

[[!UAX44]]

For the <code>&lt;narrow&gt;</code> tag,

the mapping is from the code point to the decomposition

(minus <code>&lt;narrow&gt;</code> tag),

and for the <code>&lt;wide&gt;</code> tag,

the mapping is from the decomposition

(minus the <code>&lt;wide&gt;</code> tag)

back to the original code point.

<wpt>

text-transform/text-transform-fullwidth-001.xht

text-transform/text-transform-fullwidth-002.xht

text-transform/text-transform-fullwidth-004.xht

text-transform/text-transform-fullwidth-005.xht

text-transform/text-transform-fullwidth-006.html

text-transform/text-transform-fullwidth-007.html

</wpt>

The mappings for [=small Kana=] to [=full-size Kana=] are defined in [[#small-kana]].

<h3 id=word-space-transform oldids="word-boundary-expansion">

Expanding Between Words: the 'word-space-transform' property</h3>

<wpt title="

This section has generally good coverage.

Missing tests:

* no test of Animation type

"></wpt>

<pre class="propdef">

Name: word-space-transform

Value: none | [ space | ideographic-space ] && auto-phrase?

Initial: none

Applies to: text

Inherited: yes

Percentages: N/A

Computed value: as specified

Animation type: discrete

</pre>

<wpt>

parsing/word-space-transform-computed.html

parsing/word-space-transform-invalid.html