If the main body of text is in a foreign language with occasional words or passages of English interspersed, e.g. by way of commentary or explanation, it is recommended that the function of the code switch indicators should be reversed, so that they enclose the UEB material. Explain this reversal in a transcriber's note.

For a literary work in which English and one or more other languages are interspersed freely with no typographical or other distinction, consider the braille codes of the languages involved and the issue of ambiguity in determining whether to use UEB contractions and how to represent accented letters. Do not mix UEB signs and foreign code signs for any particular print character or braille indicator. 

Note: The following example is a mix of English and Spanish. In this example, foreign code signs are used for accented letters since it is expected that readers would be familiar with them. Uncontracted braille is used to avoid ambiguity. UEB signs are used for punctuation and indicators.

The purpose of code switching is to indicate text which is transcribed in a braille code other than UEB. This may include:6 

• braille codes for languages other than English, such as Afrikaans, French, German, Spanish, Vietnamese 

• IPA Braille: An Updated Tactile Representation of the International Phonetic Alphabet [see 14.4] 

• New International Manual of Braille Music Notation [see 14.5]

• The Nemeth Braille Code for Mathematics and Science Notation [see 14.6] 

• other non-UEB braille codes for subjects such as mathematics, chemistry, computer science (assuming the transcriber has a special reason for switching, which in general is not necessary in UEB) 

• historical braille codes 

• proposed braille codes

When a text is to be read in hardcopy braille, do not use code switching indicators when the nature and extent of the non-UEB text can be determined by the context or format.

In situations where code switching indicators are not used, ensure that the format or position of the non-UEB material is clear to the reader. Often the text itself will make it obvious, for example: when the introduction of a bilingual dictionary explains that the entry word in French is followed by its pronunciation in IPA; when the text has two columns headed "Spanish" and "English"; or when the text states that the words in German are in bold. If the text does not explicitly draw attention to the non-UEB material, use a transcriber's note to explain the format or position of non-UEB braille codes.

Use code switching indicators for non-UEB material when writing braille that will be translated into print or where context and format cues are not obvious or meaningful, for example when a file will be read electronically. 

Use code switching indicators when the non-UEB braille would be ambiguous and when the nature and extent of the non-UEB text cannot be determined by the context or format.

When code switching indicators with identifiers are used, explain them either on a special symbols page or in a transcriber's note positioned before the affected material. [See 14.3.3.]

Place the non-UEB word indicator immediately preceding the symbols-sequence to which it applies. Its effect is terminated by the next space or by the next non-UEB word terminator. 

In the rare instance where the closing non-UEB passage indicator could realistically be misread as a symbol within the non-UEB code, instead use an opening non-UEB passage indicator augmented with the identifier "en" (for English) to indicate that UEB is resuming. If even this would be misread, the transcriber may devise a safe indicator to resume UEB.