Editing Braille (section)

=== Derivation ===
Braille is derived from the Latin alphabet, albeit indirectly. In Braille's original system, the dot patterns were assigned to letters according to their position within the [[collating sequence|alphabetic order]] of the French alphabet of the time, with [[diacritic|accented]] letters and ''w'' sorted at the end.<ref>{{cite book |first=Madeleine Seymour |last=Loomis |date=1942 |title=The Braille Reference Book for Grades I, I.5, and II |location=New York and London |publisher=Harper & Bros. |oclc=13839990}}</ref>

Unlike print, which consists of mostly arbitrary symbols, the braille alphabet follows a logical sequence. The first ten letters of the alphabet, ''a''–''j'', use the upper four dot positions: {{Braille cell|type=text|⠁|⠃|⠉|⠙|⠑|⠋|⠛|⠓|⠊|⠚}} (black dots in the table below). These stand for the ten digits ''1''–''9'' and ''0'' in an [[alphabetic numeral system]] similar to [[Greek numerals]] (as well as derivations of it, including [[Hebrew numerals]], [[Cyrillic numerals]], [[Abjad numerals]], also Hebrew [[gematria]] and Greek [[isopsephy]]).

Though the dots are assigned in no obvious order, the cells with the fewest dots are assigned to the first three letters (and lowest digits), ''abc'' = ''123'' ({{Braille cell|type=text|⠁|⠃|⠉}}), and to the three vowels in this part of the alphabet, ''aei'' ({{Braille cell|type=text|⠁|⠑|⠊}}), whereas the even digits ''4'', ''6'', ''8'', ''0'' ({{Braille cell|type=text|⠙|⠋|⠓|⠚}}) are right angles.

The next ten letters, ''k''–''t'', are identical to ''a''–''j'' respectively, apart from the addition of a dot at position 3 (red dots in the bottom left corners of the cells in the table below): {{Braille cell|type=text|⠅|⠇|⠍|⠝|⠕|⠏|⠟|⠗|⠎|⠞}}:

: {| class="wikitable" style="text-align:center"
|+ Derivation (colored dots) of the 26 braille letters of the [[ISO basic Latin alphabet|basic Latin alphabet]] from the 10 numeric digits (black dots)
|-
|[[File:Braille A1.svg|40px]]||[[File:Braille B2.svg|40px]]||[[File:Braille C3.svg|40px]]||[[File:Braille D4.svg|40px]]||[[File:Braille E5.svg|40px]]||[[File:Braille F6.svg|40px]]||[[File:Braille G7.svg|40px]]||[[File:Braille H8.svg|40px]]||[[File:Braille I9.svg|40px]]||[[File:Braille J0.svg|40px]]
|-
|[[a]]/[[1 (number)|1]]||[[b]]/[[2 (number)|2]]||[[c]]/[[3 (number)|3]]||[[d]]/[[4 (number)|4]]||[[e]]/[[5 (number)|5]]||[[f]]/[[6 (number)|6]]||[[g]]/[[7 (number)|7]]||[[h]]/[[8 (number)|8]]||[[i]]/[[9 (number)|9]]||[[j]]/[[0 (number)|0]]
|-
|[[File:Braille K colored.svg|40px]]||[[File:Braille L colored.svg|40px]]||[[File:Braille M colored.svg|40px]]||[[File:Braille N colored.svg|40px]]||[[File:Braille O colored.svg|40px]]||[[File:Braille P colored.svg|40px]]||[[File:Braille Q colored.svg|40px]]||[[File:Braille R colored.svg|40px]]||[[File:Braille S colored.svg|40px]]||[[File:Braille T colored.svg|40px]]
|-
|[[k]]||[[l]]||[[m]]||[[n]]||[[o]]||[[p]]||[[q]]||[[r]]||[[s]]||[[t]]
|-
|[[File:Braille U colored.svg|40px]]||[[File:Braille V colored.svg|40px]]||[[File:Braille X colored.svg|40px]]||[[File:Braille Y colored.svg|40px]]||[[File:Braille Z colored.svg|40px]]|| colspan="4" rowspan="2" | ||[[File:Braille W colored.svg|40px]]
|-
|[[u]]||[[v]]||[[x]]||[[y]]||[[z]]||[[w]]
|}

The next ten letters (the next "[[wikt:decade#English|decade]]") are the same again, but with dots also at both position 3 and position 6 (green dots in the bottom rows of the cells in the table above). Here ''w'' was left out as it was not part of the official French alphabet in Braille's time; the French order of the decade was ''u v x y z ç é à è ù'' ({{Braille cell|type=text|⠥|⠧|⠭|⠽|⠵|⠯|⠿|⠷|⠮|⠾}}).{{NoteTag|The values of the Latin letters after ''z'' differ from language to language; these are Braille's assignments for rendering French.}}

The next ten letters, ending in ''w'', are the same again, except that for this series position 6 (purple dot in the bottom right corner of the cell in the table above) is used without a dot at position 3. In French braille these are the letters ''â ê î ô û ë ï ü œ w'' ({{Braille cell|type=text|⠡|⠣|⠩|⠹|⠱|⠫|⠻|⠳|⠪|⠺}}). ''W'' had been tacked onto the end of 39 letters of the French alphabet to accommodate English.

The ''a''–''j'' series shifted down by one dot space ({{Braille cell|type=text|⠂|⠆|⠒|⠲|⠢|⠖|⠶|⠦|⠔|⠴}}) is used for punctuation. Letters ''a'' {{braille cell|a}} and ''c'' {{braille cell|c}}, which only use dots in the top row, were shifted two places for the apostrophe and hyphen: {{Braille cell|type=text|⠄|⠤}}. (These are also the decade diacritics, on the left in the table below, of the second and third decade.)

In addition, there are ten patterns that are based on the first two letters ({{braille cell|a|b}}) with their dots shifted to the right; these were assigned to non-French letters (''ì ä ò'' {{Braille cell|type=text|⠌|⠜|⠬}}), or serve non-letter functions: {{Braille cell|type=text|⠈}} (superscript; in English the accent mark), {{Braille cell|type=text|⠘}} (currency prefix), {{Braille cell|type=text|⠨}} (capital, in English the [[decimal point]]), {{Braille cell|type=text|⠼}} ([[number sign]]), {{Braille cell|type=text|⠸}} (emphasis mark), {{Braille cell|type=text|⠐}} (symbol prefix).

: {| class="wikitable noresize" styel="text-align:center"
|+ The 64 modern braille cells{{anchor|upper-half cells}}{{NoteTag|[[File:Final braille.png|thumb|upright=0.9|The final form of Braille's alphabet, according to Henri (1952). "(1)" indicates markers for musical and mathematical notation.]]
The characters here have been arranged by decade, with the decade diacritics listed on the left, and supplementary characters listed on the right according to their diacritic. See [[1829 braille]], where the 12 characters listed in the first line are used for shorthand and are found in this order for the 12 notes of plainsong notation, and [[French Braille]], where the "final" form of Braille's alphabet is laid out in the same way. However, modern tables often organize the supplementary characters differently: those with a dot 3 are listed as a 6th decade of 6 characters, and those with dots only on the right side are listed as a 7th decade of 7 characters, without anything in common with the characters listed above them in those columns.}}
!colspan=2| decade || ||colspan=10| numeric sequence || ||colspan=2| shift right
|-
!1st
|[[File:Braille NULL.svg|40px]] ||
|[[File:Braille A1.svg|40px]]
|[[File:Braille B2.svg|40px]]
|[[File:Braille C3.svg|40px]]
|[[File:Braille D4.svg|40px]]
|[[File:Braille E5.svg|40px]]
|[[File:Braille F6.svg|40px]]
|[[File:Braille G7.svg|40px]]
|[[File:Braille H8.svg|40px]]
|[[File:Braille I9.svg|40px]]
|[[File:Braille J0.svg|40px]] ||
|[[File:Braille Accent.svg|40px]]
|[[File:Braille Currency.svg|40px]]
|-
!2nd
|[[File:Braille Apostrophe colored.svg|40px|' (apostrophe)]] ||
|[[File:Braille K colored.svg|40px]]
|[[File:Braille L colored.svg|40px]]
|[[File:Braille M colored.svg|40px]]
|[[File:Braille N colored.svg|40px]]
|[[File:Braille O colored.svg|40px]]
|[[File:Braille P colored.svg|40px]]
|[[File:Braille Q colored.svg|40px]]
|[[File:Braille R colored.svg|40px]]
|[[File:Braille S colored.svg|40px]]
|[[File:Braille T colored.svg|40px]] ||
|[[File:Braille ST colored.svg|40px]]
|[[File:Braille Ä colored.svg|40px]]
|-
!3rd
|[[File:Braille Hyphen colored.svg|40px|- (hyphen)]] ||
|[[File:Braille U colored.svg|40px]]
|[[File:Braille V colored.svg|40px]]
|[[File:Braille X colored.svg|40px]]
|[[File:Braille Y colored.svg|40px]]
|[[File:Braille Z colored.svg|40px]]
|[[File:Braille Ç colored.svg|40px]]
|[[File:Braille É colored.svg|40px]]
|[[File:Braille À colored.svg|40px]]
|[[File:Braille È colored.svg|40px]]
|[[File:Braille Ù colored.svg|40px]] ||
|[[File:Braille Ò colored.svg|40px]]
|[[File:Braille Number colored.svg|40px|# (number)]]
|-
!4th
|[[File:Braille Capital colored.svg|40px|UPPERCASE (capital)]] ||
|[[File:Braille Â colored.svg|40px]]
|[[File:Braille Ê colored.svg|40px]]
|[[File:Braille Î colored.svg|40px]]
|[[File:Braille Ô colored.svg|40px]]
|[[File:Braille Û colored.svg|40px]]
|[[File:Braille Ë colored.svg|40px]]
|[[File:Braille Ï colored.svg|40px]]
|[[File:Braille Ü colored.svg|40px]]
|[[File:Braille Ö colored.svg|40px]]
|[[File:Braille W colored.svg|40px]] ||
|[[File:Braille Decimal colored.svg|40px|. (decimal point)]]
|[[File:Braille Cursive colored.svg|40px]]
|-
!5th
! <span style="color:#006060">shift<br />down</span>
|
|[[File:Braille Comma colored.svg|40px|, (comma)]]
|[[File:Braille Semicolon colored.svg|40px|; (semicolon)]]
|[[File:Braille Colon colored.svg|40px|: (colon)]]
|[[File:Braille Period colored.svg|40px|. (period)]]
|[[File:Braille QuestionMark colored.svg|40px|? (question mark)]]
|[[File:Braille ExclamationPoint colored.svg|40px|! (exclamation point)]]
|[[File:Braille Bracket colored.svg|40px]]
|[[File:Braille QuoteOpen colored.svg|40px|“ (quote open)]]
|[[File:Braille Asterisk colored.svg|40px|* (asterisk)]]
|[[File:Braille QuoteClose colored.svg|40px|” (quote close)]] ||
|[[File:Braille ContractionPrefix colored.svg|40px]]
|[[File:Braille Correction colored.svg|40px]]
|}

The first four decades are similar in that the numeric sequence is extended by adding the decade dots, whereas in the fifth decade it is extended by shifting it downward.

Originally there had been nine decades. The fifth through ninth used dashes as well as dots, but they proved to be impractical to distinguish by touch under normal conditions and were soon abandoned. From the beginning, these additional decades could be substituted with what we now know as the number sign ({{Braille cell|type=text|⠼}}) applied to the earlier decades, though that only caught on for the digits (the old 5th decade being replaced by {{Braille cell|type=text|⠼}} applied to the 1st decade). The dash occupying the top row of the original sixth decade was simply omitted, producing the modern fifth decade. (See [[1829 braille]].)