If the word or phrase is not likely to be understood universally, italicize and provide an explanation: errare humanum est, a Latin phrase meaning “to err is human.” Certain terms may be used without explanation if they are clear in the context: She graduated summa cum laude.
Some foreign words and their abbreviations have been accepted into the English language and need not be italicized; for example: bon voyage; El Niño; emeritus, emerita; étude; haute cuisine, haute couture; glasnost, perestroika; in vitro; protégé; résumé; versus, vs.; et cetera, etc. If in doubt, assume that the word is too familiar in English to be treated as foreign.
When using foreign words (including proper names), include the appropriate accent marks: authors include Guiraldes, Carpentier, Cortàzar, and García Márquez. However, if the text will appear in a computer markup language (HTML, XML), be aware that these special characters require specific codes to render properly in browsers. A chart of the codes for some commonly used special characters is included at the end of this guide; a full list is available at www.w3.org.