Original: One example compares the contractions "ll", meaning little, and "lr", meaning letter from Barry Hampshire's "Working with Braille".
Simplified: Encoding As originally conceived by Louis Braille, a sequence of characters, using the top 4 dots of the braille cell, represents letters "a" through "j". Dot 3 is added to each of the "a" through "j" symbols to give letters "k" through "t". Both of the bottom dots (dots 3 and 6) are added to the symbols for "a" through "e" to give letters "u", "v", "x", "y", and "z". For example, the character with dots 2-3-5 (the letter "f" lowered in the braille cell) stands for "ff" when used in the middle of a word.