The editor of any self-respecting printed medium would not dream of confusing the em dash (—), en dash (–) and hyphen (-) within the publication. And while most of us could not articulate the difference, we
would mostly find ourselves using the correct punctuation mark when hand-writing a letter.

But what has happened online?

Most websites have no regard for the distinction between these — any many other — marks of punctuation. Mostly, this is because the standard keyboard does not allow without RSI-inducing keyboard sequences.

If you are the sort who seeks professionalism in everything you do, you can respect the purpose of these time-tested punctuation marks by first understanding when to use which, and then how to actually type them or include them in a website.

1. Em Dash (—): Denotes a pause in thought, a parenthetical statement, or — more casually — an afterthought. In a web page, a web developer can include — to represent the character. When typing, you can input a character by holding ALT and typing 0151 on the numpad.
2. En Dash (–): Denotes a range, especially of numbers, such as $100–150. – in a web page or ALT-0150 on a keyboard.
3. Hyphen (-): Used for the hyphenation of words (co-ordination; able-minded; pre- and post- touring.) Just use the keyboard key for this one.

Now don’t get me started on apostrophes and quote marks being “encompassed” by the tick character on the keyboard…