Hyphens, En Dashes, Em Dashes

Q. When referring to a telephone call for which the calling party is not charged, is it (a) a “toll free call,” (b) a “tollfree call,” or (c) a “toll-free call.” My own preference is for c first, then b. However, our marketing bunch uses a. Your thoughts would be greatly appreciated. This is driving me nuts (or at least nuttier than usual).

A. Chicago hyphenates all “free” words in any position: toll-free call; the call was toll-free. See 7.85, section 3, under “free.”