Foreign letters. Letters must be valid in the language being spoken. For example, “ж” is a letter in the Russian alphabet but is never used in English and so should never appear in any English source text.
Lèt etranje. Lèt yo dwe valab nan lang yo pale a. Pou egzanp, "ж" se yon lèt nan alfabè Ris la men li pa janm itilize nan lang angle e konsa pa ta dwe janm parèt nan nenpòt tèks sous angle.