10.1.9. Quotation marks
Use single quotation marks for quotations, but use double quotation marks for quotations within quotations. If there should be yet another quotation within the second quotation, revert to single quotation marks (see also Section 4.2.3.)
The American government favours ‘a two-way street in arms procurement’.
Walther Rathenau once said: ‘We stand or fall on our economic performance.’
Do not enclose titles of books, newspapers or foreign expressions in quotation marks as they are usually displayed in italics. It is not necessary to use quotation marks as well as bold or italics. (See Section 5.9.4 for use of italics and quotation marks in bibliographies.)
the Agriculture Council, the Human Factors Committee, etc.
Quotation marks should not be used in combination with ‘so-called’ to highlight the description that follows (e.g. ‘The resolution was passed by the so-called “European legislator”’). First, the use of quotation marks makes the expression ‘so-called’ redundant, and second, the combination of both devices strongly implies that the authors wish to distance themselves from the term used or cast doubt on its accuracy or correctness.