Use italics for foreign phrases, unless they are commonly used in English.

​An exception is eigenstates, which, although a German word, should be written in roman.

Also use italics for genus and species; exhibitions and campaigns; a complete literary work (a book, a play, an album, a magazine, journal, video game, etc. but NOT the title of a chapter, an act, an event, a song or an article – these take double quotation marks). Also italicise letters that refer to quantities (e = mc²) and vehicles that carry passengers, such as Titanic