Category:Braille letters (8 dots)

1	4
2	5
3	6
7	8

Standard numbering of dots in 8-dot Braille patterns.

In this category, the images of 8-dots Braille patterns are named by numbering dots 1 to 6 vertically only on the top 3 rows like in the 6-dots patterns, adding dots 7 and 8 horizontally on the 4th row (as shown in the table on the left). These characters are assigned in the Unicode and ISO/IEC 10646 standards in the "Braille Patterns" block (in the subrange U+2800..U+28FF) and ordered so that the lowest 8 bits of their code point values are numbered in the same order as this traditional numbering of dots in standard Braille patterns.

The 64 first symbols in this set are considered equivalent (semantically) to the set of 6-dot patterns for Braille readers and are then used the same way. But in this category the images are displaying the positions of the two unused dots at the bottom (so their relative image height will be larger).

The extra 192 symbols that are possible with the 8-dot patterns may be used for scripts (such as large syllabaries or ideographs) requiring a larger number of distinctions with a reduced total number of symbols for the same text, or may be used for technical notations in specific domains, or in private use sets of abbreviations explained by authors of each collection of Braille documents. However they require an advanced training for deaf readers to improve their tactile skills, so they are avoided most of the time as they slow down the reading and may cause confusion.

0	7
1	4
2	5
3	6

Alternate numbering of dots in 8-dot Kantenji Braille patterns.

For this reason, languages normally written with large syllabaries or ideographs will be preferably transliterated into another well known (but reduced) alphabet (using transliteration standards already used for the same languages) before being converted into suites of Braille patterns. Most texts converted into series of images of Braille patterns should preferably use the other smaller set of 6-dots Braille patterns, for better accessibility: see the Category:Braille letters (6 dots), where the 2 bottom dots are only used as additional styles or annotations (e.g. to denote emphasis, underlining, or document-specific conventions described elsewhere in the document).

Note however that the standard numbering of dots for 8-dot patterns is different for the Kantenji Braille system used in Japan (which needs the full set of 8-dot patterns, without necessarily using a transliteration to a smaller alphabet prior to the conversion): Kantenji dots are numbered from 0 to 7 (instead of 1 to 8), with the two upper dots in Kantenji Braille patterns numbered 0 and 7; this 8-dot system is using a single pattern for each distinctive Kana, digits, punctuations or marks, or 2 patterns for most common Kanjis. The two upper dots may be used to represent dakuten or handakuten marks on top of kana letters or switch between Kanas, Kanji and Romaji. When converting Kantenji Braille patterns to Unicode, they must be reordered using the standard numbering for correct rendering.