Line Break Behavior Details

The following table enumerates the line breaking semantics of all characters in a manner consistent with ​CSS3 Text.

The columns of the table are defined as follows:

• Code - Unicode code point (in hexadecimal), except - which means all other characters not explicitly listed
• UAX14 - Line breaking class assigned by ​UAX14
• ICU() - Behavior implemented by ​ICU when primary language subtag of locale is not specified, not 'ja', or otherwise not explicitly supported
• ICU(ja) - Behavior implemented by ​ICU when primary language subtag of locale is 'ja' (or equivalent)
• Loose() - Behavior prescribed by CSS3 when line-break is loose and content language is not Chinese, Japanese, or Korean
• Loose(cjk) - Behavior prescribed by CSS3 when line-break is loose and content language is Chinese, Japanese, or Korean
• Normal() - Behavior prescribed by CSS3 when line-break is normal and content language is not Chinese, Japanese, or Korean
• Normal(cjk) - Behavior prescribed by CSS3 when line-break is normal and content language is Chinese, Japanese, or Korean
• Strict() - Behavior prescribed by CSS3 when line-break is strict and content language is not Chinese, Japanese, or Korean
• Strict(cjk) - Behavior prescribed by CSS3 when line-break is strict and content language is Chinese, Japanese, or Korean
• Character Name - Unicode character name

The values of the UAX14 column designate (a subset of the) line breaking classes defined by UAX14 as follows:

• BA - Break After
• CJ - Conditional Japanese Starter
• EX - Exclamation/Interrogation
• IN - Inseparable
• IS - Infix Numeric Separator
• NS - Nonstarters
• PO - Postfix Numeric
• PR - Prefix Numeric
• - - as otherwise defined by ​UAX14

The values of the ICU() through Strict(ja) columns designate the following breaking behavior:

• A - break permitted after
• B - break permitted before
• B/A - break permitted before or after
• XA - break excluded after
• XB - break excluded before
• XP - break excluded between any pair in class
• - - as otherwise defined by default line breaking behavior

  ISSUE: Need to verify behavior for U+2010 (hyphen) and U+2013 (en dash) below. UAX14 characterizes as BA (break permitted after) but doesn't address break before behavior, while CSS3 Text prescribes certain break before behavior but not break after behavior.

Code	UAX14	ICU()	ICU(ja)	Loose()	Loose(cjk)	Normal()	Normal(cjk)	Strict()	Strict(cjk)	Character Name
0021	EX	XB	XB	-	B/A	-	XB	-	XB	exclamation mark
0024	PR	XA	XA	-	B/A	-	XA	-	XA	dollar sign
0025	PO	XB	XB	-	B/A	-	XB	-	XB	percent sign
003A	IS	XB	XB	-	B/A	-	XB	-	XB	colon
003B	IS	XB	XB	-	B/A	-	XB	-	XB	semicolon
003F	EX	XB	XB	-	B/A	-	XB	-	XB	question mark
00A2	PO	XB	XB	-	B/A	-	XB	-	XB	cent sign
00A3	PR	XA	XA	-	B/A	-	XA	-	XA	pound sign
00A5	PR	XA	XA	-	B/A	-	XA	-	XA	yen sign
00B0	PO	XB	XB	-	B/A	-	XB	-	XB	degree sign
2010	BA	A	A	-	B/A	-	B/A	-	XB	hyphen
2013	BA	A	A	-	B/A	-	B/A	-	XB	en dash
2025	IN	XP	XP	B/A	B/A	XP	XP	XP	XP	two dot leader
2026	IN	XP	XP	B/A	B/A	XP	XP	XP	XP	ellipsis
2030	PO	XB	XB	-	B/A	-	XB	-	XB	per mille sign
2032	PO	XB	XB	-	B/A	-	XB	-	XB	prime
2033	PO	XB	XB	-	B/A	-	XB	-	XB	double prime
203C	NS	XB	XB	-	B/A	-	XB	-	XB	double exclamation mark
2047	NS	XB	XB	-	B/A	-	XB	-	XB	double question mark
2048	NS	XB	XB	-	B/A	-	XB	-	XB	question exclamation mark
2049	NS	XB	XB	-	B/A	-	XB	-	XB	exclamation question mark
20AC	PR	XA	XA	-	B/A	-	XA	-	XA	euro sign
2103	PO	XB	XB	-	B/A	-	XB	-	XB	degree celsius
2116	PR	XA	XA	-	B/A	-	XA	-	XA	numero sign
3005	NS	XB	XB	B/A	B/A	XB	XB	XB	XB	ideographic iteration mark
301C	NS	XB	XB	-	B/A	-	B/A	-	XB	wave dash
303B	NS	XB	XB	B/A	B/A	XB	XB	XB	XB	vertical ideographic iteration mark
3041	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small a
3043	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small i
3045	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small u
3047	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small e
3049	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small o
3063	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small tu
3083	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small ya
3085	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small yu
3087	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small yo
308E	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small wa
3095	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small ka
3096	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	hiragana letter small ke
309D	NS	XB	XB	B/A	B/A	XB	XB	XB	XB	hiragana iteration mark
309E	NS	XB	XB	B/A	B/A	XB	XB	XB	XB	hiragana voiced iteration mark
30A0	NS	XB	XB	-	B/A	-	B/A	-	XB	katakana-hiragana double hyphen
30A1	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small a
30A3	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small i
30A5	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small u
30A7	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small e
30A9	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small o
30C3	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small tu
30E3	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ya
30E5	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small yu
30E7	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small yo
30EE	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small wa
30F5	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ka
30F6	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ke
30FB	NS	XB	XB	-	B/A	-	XB	-	XB	katakana middle dot
30FC	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana-hiragana prolonged sound mark
30FD	NS	XB	XB	B/A	B/A	XB	XB	XB	XB	katakana iteration mark
30FE	NS	XB	XB	B/A	B/A	XB	XB	XB	XB	katakana voiced iteration mark
31F0	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ku
31F1	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small si
31F2	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small su
31F3	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small to
31F4	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small nu
31F5	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ha
31F6	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small hi
31F7	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small hu
31F8	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small he
31F9	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ho
31FA	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small mu
31FB	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ra
31FC	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ri
31FD	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ru
31FE	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small re
31FF	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	katakana letter small ro
FF01	EX	XB	XB	-	B/A	-	XB	-	XB	fullwidth exclamation mark
FF04	PR	XA	XA	-	B/A	-	XA	-	XA	fullwidth dollar sign
FF05	PO	XB	XB	-	B/A	-	XB	-	XB	fullwidth percent sign
FF1A	NS	XB	XB	-	B/A	-	XB	-	XB	fullwidth colon
FF1B	NS	XB	XB	-	B/A	-	XB	-	XB	fullwidth semicolon
FF1F	EX	XB	XB	-	B/A	-	XB	-	XB	fullwidth question mark
FF65	NS	XB	XB	-	B/A	-	XB	-	XB	halfwidth katakana middle dot
FF67	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small a
FF68	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small i
FF69	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small u
FF6A	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small e
FF6B	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small o
FF6C	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small ya
FF6D	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small yu
FF6E	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small yo
FF6F	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana letter small tu
FF70	CJ	XB	B/A	B/A	B/A	B/A	B/A	XB	XB	halfwidth katakana-hiragana prolonged sound mark
FFE0	PO	XB	XB	-	B/A	-	XB	-	XB	fullwidth cent sign
FFE1	PR	XA	XA	-	B/A	-	XA	-	XA	fullwidth pound sign
FFE5	PR	XA	XA	-	B/A	-	XA	-	XA	fullwidth yen sign
-	-	-	-	-	-	-	-	-	-	all other characters

Implementation Details

• If -webkit-line-break is auto, content language is not Chinese, Japanese, or Korean, and ICU does not provide a tailored set of rules that applies to the content language, then use the ICU() column's behavior;
• If -webkit-line-break is auto, content language is not Chinese, Japanese, or Korean, and ICU does provide a tailored set of rules that applies to the content language, then use the ICU() column's behavior modulo application of tailored rules;
• If -webkit-line-break is auto and content language is Chinese, Japanese, or Korean, then use the Normal(cjk) column's behavior;
• If -webkit-line-break is loose and content language is not Chinese, Japanese, or Korean, then use the Loose() column's behavior;
• If -webkit-line-break is loose and content language is Chinese, Japanese, or Korean, then use the Loose(cjk) column's behavior;
• If -webkit-line-break is normal and content language is not Chinese, Japanese, or Korean, then use the Normal() column's behavior;
• If -webkit-line-break is normal and content language is Chinese, Japanese, or Korean, then use the Normal(cjk) column's behavior;
• If -webkit-line-break is strict and content language is not Chinese, Japanese, or Korean, then use the Strict() column's behavior;
• If -webkit-line-break is strict and content language is Chinese, Japanese, or Korean, then use the Strict(cjk) column's behavior;
• If -webkit-line-break is after-white-space, then use the procedure defined in Handling of after-white-space.

For implementation purposes, content language is determined as described by ​to determine the language of a node.

For implementation purposes, default line breaking behavior is interpreted as the behavior implemented by ​ICU when applying either ICU's default rules or locale specific rules tailored to an identified content language.

Handling of after-white-space

ISSUE: To be supplied.