Q. Hello. CMOS 3.34 (“Crediting material obtained free of charge”) says “For material that the author has obtained free and without restrictions on its use, the credit line may use the word courtesy.” What exactly does “without restrictions on its use” mean? Does this mean that, if I’ve gotten permission to use a photo in a specific essay I’m writing, I can’t use “courtesy of” because the permission is only for that specific project?
A. Rights holders can put various restrictions on the use of items they give permission for: they can disallow cropping a photo or resizing or recoloring it or integrating it into a collage. They can prohibit a quotation from being used in an advertisement or from being altered in any way. They can prohibit resale, or repackaging, or use without full credit. If there are restrictions on your photo, they will be listed at the place you got it. Sometimes you have to click on a link to see the specific restrictions. If your photo is without restrictions and therefore does not require a credit, it’s polite to give credit anyway: “Courtesy of Terry Adams.”