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In Unicode, Braille is represented in a block called "Braille Patterns" (U+2800..U+28FF). The block contains all 256 possible patterns of an 8-dot Braille cell, thereby including the complete 6-dot cell range.^[1]

Symbols, not a script

In Unicode the Braille characters are not defined into any script. That is, the patterns are available as symbols, without connection to an alphabetic letter or a number. This is because the same symbol can be used in multiple scripts, e.g. as a Latin character, a Vietnamese character, a Chinese character and a digit. Example: while ⠓ (U+2813 BRAILLE PATTERN DOTS-125) is defined, there is no reference to the letter "H", as exists in basic Latin Braille. In other Braille languages the same pattern ⠓ can have a different meaning; in the original Latin Braille the same ⠓ can represent digit "8". For this reason (a dot-pattern is not a letter), Unicode declares that strictly spoken, Braille patterns are 'symbols', not a 'script'. The General Property is "So" (Symbol, other), not "Lo" (Letter, other). Although beyond that declaration, Braille is treated as a script multiple places. E.g. the character property "Script" for the 256 Braille code points is ISO 15924 "Brai", for Braille. This way searching users and programs are lead to the right place.

Identifying, naming and ordering

The coding is in accordance with ISO/TR 11548-1 Communication aids for blind persons.^[1] Unicode uses the standard dot-numbering 1 to 8. Historically only the 6-dot cell was used in Braille. The lower two dots were added later, which explains the irregular numbering 1-2-3-7 in the left column and 4-5-6-8 in the right column. There is no distinction between 6-dot and 8-dot patterns.

The Unicode name of a specific pattern mentions the raised dots: U+2813 ⠓ BRAILLE PATTERN DOTS-125 has dots 1, 2 and 5 raised. By exception, the zero dot raised pattern is named BRAILLE PATTERN BLANK.

In the 8-dot cell each dot individually can be raised or not. That creates 8²=256 different patterns. By mapping each of the eight dots to a bit in a byte (in a Low Endian order), and by defining "0"/"1" for not raised/raised per bit, every specific pattern generates a identifying binary number. So the pattern with dots 1-2-5 raised would yield (00001011)₂, equivalent to (13)₁₆ or (19)₁₀.

In the Unicode block, the patterns are ordered according to this number, from the offset (2800)₁₆.

**Braille cell examples**
Unicode character	U+2813	U+28C7	U+28FF
Braille symbol	⠓	⣇	⣿
Name	BRAILLE PATTERN DOTS-125	BRAILLE PATTERN DOTS-12378	BRAILLE PATTERN DOTS-12345678
Dot numbers available	`1 2 3 4 5 6 7 8`	`1 2 3 4 5 6 7 8`	`1 2 3 4 5 6 7 8`
Dot raised=1	`1 1 0 0 1 0 0 0`	`1 1 1 0 0 0 1 1`	`1 1 1 1 1 1 1 1`
Binary value (by reversed order)	`0 0 0 1 0 0 1 1₂`	`1 1 0 0 0 1 1 1₂`	`1 1 1 1 1 1 1 1₂`
Decimal value	`19₁₀`	`199₁₀`	`255₁₀`
Hexadecimal value	`13₁₆`	`C7₁₆`	`FF₁₆`
Into block, offset `U+2800₁₆`	`2800₁₆+13₁₆=2813₁₆`	`2800₁₆+C7₁₆=28C7₁₆`	`2800₁₆+FF₁₆=28FF₁₆`

There is no regular mapping to the Braille ASCII numbering.

Chart

When using punching, the filled (black) dots are to be punched.

Braille Patterns^[1] Official Unicode Consortium code chart (PDF)
	0	1	2	3	4	5	6	7	8	9	A	B	C	D	E	F
U+280x	⠀	⠁	⠂	⠃	⠄	⠅	⠆	⠇	⠈	⠉	⠊	⠋	⠌	⠍	⠎	⠏
U+281x	⠐	⠑	⠒	⠓	⠔	⠕	⠖	⠗	⠘	⠙	⠚	⠛	⠜	⠝	⠞	⠟
U+282x	⠠	⠡	⠢	⠣	⠤	⠥	⠦	⠧	⠨	⠩	⠪	⠫	⠬	⠭	⠮	⠯
U+283x	⠰	⠱	⠲	⠳	⠴	⠵	⠶	⠷	⠸	⠹	⠺	⠻	⠼	⠽	⠾	⠿
(end of 6-dot cell patterns)
U+284x	⡀	⡁	⡂	⡃	⡄	⡅	⡆	⡇	⡈	⡉	⡊	⡋	⡌	⡍	⡎	⡏
U+285x	⡐	⡑	⡒	⡓	⡔	⡕	⡖	⡗	⡘	⡙	⡚	⡛	⡜	⡝	⡞	⡟
U+286x	⡠	⡡	⡢	⡣	⡤	⡥	⡦	⡧	⡨	⡩	⡪	⡫	⡬	⡭	⡮	⡯
U+287x	⡰	⡱	⡲	⡳	⡴	⡵	⡶	⡷	⡸	⡹	⡺	⡻	⡼	⡽	⡾	⡿
U+288x	⢀	⢁	⢂	⢃	⢄	⢅	⢆	⢇	⢈	⢉	⢊	⢋	⢌	⢍	⢎	⢏
U+289x	⢐	⢑	⢒	⢓	⢔	⢕	⢖	⢗	⢘	⢙	⢚	⢛	⢜	⢝	⢞	⢟
U+28Ax	⢠	⢡	⢢	⢣	⢤	⢥	⢦	⢧	⢨	⢩	⢪	⢫	⢬	⢭	⢮	⢯
U+28Bx	⢰	⢱	⢲	⢳	⢴	⢵	⢶	⢷	⢸	⢹	⢺	⢻	⢼	⢽	⢾	⢿
U+28Cx	⣀	⣁	⣂	⣃	⣄	⣅	⣆	⣇	⣈	⣉	⣊	⣋	⣌	⣍	⣎	⣏
U+28Dx	⣐	⣑	⣒	⣓	⣔	⣕	⣖	⣗	⣘	⣙	⣚	⣛	⣜	⣝	⣞	⣟
U+28Ex	⣠	⣡	⣢	⣣	⣤	⣥	⣦	⣧	⣨	⣩	⣪	⣫	⣬	⣭	⣮	⣯
U+28Fx	⣰	⣱	⣲	⣳	⣴	⣵	⣶	⣷	⣸	⣹	⣺	⣻	⣼	⣽	⣾	⣿
Notes 1.^ As of Unicode version 15.1

References

^ ^a ^b Unicode Chapter 15, section 15.10

[Unicode_ch15-1] Unicode Chapter 15, section 15.10

[1]

Revision as of 19:38, 10 June 2010 edit DePiep (talk \| contribs) Extended confirmed users 294,285 edits →‎Identifying, naming and ordering ← Previous edit		Revision as of 19:39, 10 June 2010 edit undo DePiep (talk \| contribs) Extended confirmed users 294,285 edits m ref fix Next edit →
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	In '''[[Unicode]], [[Braille\|Braille]]''' is represented in a '''[[Unicode block\|block]]''' called "Braille Patterns" (<small>U+2800..U+28FF</small>). The block contains all 256 possible patterns of an 8-dot Braille cell, thereby including the complete 6-dot cell range.<ref name="Unicode ch15~~.10~~">[http://www.unicode.org/versions/Unicode5.2.0/ch15.pdf, Unicode Chapter 15], section 15.10</ref>		In '''[[Unicode]], [[Braille\|Braille]]''' is represented in a '''[[Unicode block\|block]]''' called "Braille Patterns" (<small>U+2800..U+28FF</small>). The block contains all 256 possible patterns of an 8-dot Braille cell, thereby including the complete 6-dot cell range.<ref name="Unicode ch15">[http://www.unicode.org/versions/Unicode5.2.0/ch15.pdf Unicode Chapter 15], section 15.10</ref>

	===Symbols, not a script===		===Symbols, not a script===