Dash
I recently discovered there are three types of dashes:
- hypens (-) aka the minus sign
- en dashes (–) option-hyphen
- em dashes (—) shift-option-hyphen
I’m attempting to synthesize the information at Wikipedia, since the Chicago Manual of Style page on the subject is behind a paywall. The key equivalents above are for Mac, and the rules below are for American English.
I believe that hyphens are used to separate or disambiguate parts of a single concept (in their examples, award-winning or even compound concepts like Bose-Einstein or McCain-Feingold).
En dashes should be used to separate ranges, like June 12th–July14th, or the Giants won 7–3. There should not be spaces surrounding.
Em dashes should be used for parenthetical clauses—such as this one—and also should not have spaces.
Basically, unless it’s a minus it should not have a space.
