Laurus submitted a new resource: Em Dash, En Dash, or Hyphen (Dash)? - Rules for using each dash Read more about this resource...
Concerning the last section on spaces around the em-dash: Whether you need extra space depends on the typeface and the application doing the layout. For posts where browsers will lay it out, it is often good to use a hair space or thin space on either side, not a full-sized space. On the flip side, using InDesign with name-brand OTT fonts you can expect the engine to get the spacing exactly right and don’t put additional space of your own. example—one (no space) example — two example — three example — four (hair space) It also leaves off completely the 4th kind of dash you need to know: the minus sign! This matches the horizontal part of the plus, and may look different in position and thickness as well as length compared to the other dashes. item: +23 item: −23 item: -23 Look how the last one doesn’t line up nicely, while the middle one does. In some typefaces the hyphen is a mere speck, and using it as a minus sign looks quite bad. in a row: -–—− depending on the typeface, the last one may look different, while the first three should match in appearance except for the length. Oh, and if that’s not enough, you have the non-breaking hyphen, figure dash, and the Bar which is even longer than the em-dash. S0 that’s ‐‒–—― and −.
