The Structure and Mechanics of Braille Code

Key Insight

Braille encodes all standard written language symbols—letters, numbers, and punctuation marks—using one or more raised dots within a two-by-three cell. These six dots are conventionally numbered 1 through 6. Modern Braille production involves special typewriters or embossers that punch these dots into paper. The fundamental nature of Braille dots is binary: each dot is either flat or raised. This binary characteristic means that with 6 dots, there are 2 x 2 x 2 x 2 x 2 x 2, or 2 to the power of 6, resulting in 64 unique possible codes within the system.

Louis Braille initially devised codes for the basic lowercase Latin alphabet, utilizing 25 of the 64 possible combinations, notably without a code for 'w' due to its absence in classical French. These codes reveal patterns: the first row (a through j) uses only dots 1, 2, 4, 5; the second row duplicates these patterns but adds a raised dot 3; and the third row duplicates the first but adds raised dots 3 and 6. The system has expanded over time, with 'Grade 2 Braille' being the most common version in English publications. Grade 2 Braille incorporates numerous contractions to conserve paper and accelerate reading. For example, specific letter codes, when standing alone, represent common words, accounting for 31 codes including the space with no raised dots.

Further maximizing the 64 available codes, Grade 2 Braille employs various combinations for advanced functions. Codes for letters 'a' through 'j' combined with a raised dot 6 are used for additional contractions and the letter 'w'. 'Lowered' codes, utilizing dots 2, 3, 5, 6, represent punctuation marks like the comma, semicolon, colon, period, and parentheses, depending on context. Six more codes use combinations of dots 3, 4, 5, 6 for further contractions and punctuation. A significant code, 'ble', when not part of a word, acts as a 'number indicator', making subsequent codes (which are identical to letters 'a' through 'j') represent numbers; for example, the sequence 'ble' followed by 'b', 'e', 'f' means 256. The 'capital indicator' (dot 6) is an 'escape code' that signals the immediate following letter is uppercase, as demonstrated in 'Louis Braille'. Codes that alter the meaning of subsequent codes until undone are known as 'shift codes', while those that temporarily change interpretation for a single character are 'escape codes'.