When more than one non-UEB braille code is used in a text, use a non-UEB indicator without an identifier only when its meaning is obvious or when it refers to the same code as the next previous nonUEB passage within the paragraph.

Close any non-UEB passage before opening another non-UEB passage. In other words, return to UEB first even if another non-UEB passage will start immediately.

When the non-UEB text is displayed on one or more lines separate from the UEB text, the opening and closing non-UEB passage indicators may each be placed on a line by itself.

Except in the previous instance, place non-UEB indicators at the exact point of change from UEB to non-UEB and back, unspaced from the symbols-sequence(s) which they precede or enclose. That is, do not insert spaces which are not already present in the text.

Other forms of English braille use special codes to represent mathematics and science, computer notation and other technical or specialised subjects.

When a non-UEB code provides a symbol for switching out of that code, use that symbol in preference to the non-UEB word terminator or the closing non-UEB passage indicator.

Do not use the lower groupsign for "ea" when the letters "ea" bridge a prefix and the remainder of the word.

Braille is a tactile method of reading and writing for blind people developed by Louis Braille (1809-1852), a blind Frenchman. The braille system uses six raised dots in a systematic arrangement with two columns of three dots, known as a braille cell. By convention, the dots in the left column are numbered 1, 2 and 3 from top to bottom and the dots in the right column are numbered 4, 5 and 6 from top to bottom.

Use line mode when it is advantageous to draw "lines" using standard braille cells. Line mode enables regular text and diagrammatic lines to coexist without ambiguity, even within the same diagram. Refer to: Section 7, Punctuation, for the hyphen, dash, long dash and low line; Guidelines for Technical Material, Part 4, for the lines in spatial calculations and other technical diagrams; and Part 16.7, for the lines and bonds in structural formulae used in chemistry.