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Hyphens, En Dashes, Em Dashes
Q. Some authors in the company for which I copyedit have been using an en dash, rather than a hyphen, for the negative sign in negative numbers, i.e., –3 versus -3. Some of our required fonts exaggerate the difference, and occasionally this results in negative signs of varying size in our technical documentation. I would prefer that all authors use the hyphen to create a more consistent look. As CMOS is this company’s style reference guide, I have searched through it for a recommendation regarding this topic but have not found one. Does CMOS have a preference?
A. CMOS prefers the actual minus sign, which is not the same as an en dash, in professionally typeset material. The minus sign is defined by Unicode as U+2212; the en dash is U+2013. See paragraph 11.2 and table 12.1 in CMOS for more information.