[larrymcp]

Ironically on a punctuation blog, it looks like he has a punctuation typo in his title. In the headline, the semi-colon after "hyphen" should actually be a colon. So the corrected headline is "En dash, em dash and hyphen: what’s the difference?"

A colon is used in this context, when you're introducing the question that follows.

[gverrilla]

This article is wrong all over, from where I stand. Who uses semi-colon in titles???