Dashed
T: Guys, tell me I'm not crazy. There are three types of dashes right? The dash, en-dash, and the em-dash? I just got into this big debate with my boss (we were both proofreading some black/white proofs, see) about dashes and I told her there are three kinds of dashes while she maintains there's only two: en-dash (the short dash) and em-dash. I don't have my trusty Strunk&White with me, but I seem to recall that there are three types of dashes. Or am I wrong, and there really are only two, and the shortest isn't really a dash but a hyphen?
G: OK for us non-nerds what the hey is the difference between the three (or two)? Inquiring usyosero minds want to know
C: Yes, there are three—the last one is your garden-variety hyphen, which is different from your en and em dashes
J: Ah, C beat me to it. Some people call the hyphen a "dash" (and use a "double dash" when they want to use an em-dash but don’t know how to do it) so that makes three "dashes." Technically, though, it's just the hyphen, the en-dash, and the em-dash.
X: i'm lazy. http://www.getitwriteonline.com/archive/091502.htm
Jun 4th