The Three Types of Dash

Unbeknown to many, there are ~~three main~~ many types of dash, and one of the most common typographical mistakes is to use the wrong dash for the wrong job. There are actually ~~three~~ several different types of dash and each have their own uses.

The em dash —

The em dash (—) — so named because it is the width of a capital ‘M’ — is used to delimit a separate clause in a sentence — rather like this — or similar sub-clause structures. Often used in its place however is the hyphen (-). Looking at the two side by side the difference is quite clear:

Proper em dashes:

The em dash (—), or m dash, m-rule, etc., often demarcates a parenthetical thought — like this one — or some similar interpolation.

Improper hyphens:

The em dash (—), or m dash, m-rule, etc., often demarcates a parenthetical thought - like this one - or some similar interpolation.

Spaces around em dashes

The proper setting of em dashes seems somewhat unclear. The ideal way to set them is with hair spaces ( ) either side — like this. However, IE6 doesn’t support the hair space leaving the options of either fully spaced — like this, or unspaced—like this.

Various means of spacing em dashes
Fully Spaced	Hair Spaced	Un Spaced
This — is an em — dash.	This — is an em — dash.	This—is an em—dash.

The en dash –

The en dash (–) — so named because it is half the width of a capital ‘M’ (an ‘n’) — has altogether different uses to the em dash. The en dash is used in ranges, for example:

6 – 10 years
July 10 – August 1 2009
pp. 40–42
§§ 12–13

Read more specific guidelines on Wikipedia.

The hyphen

The purpose of the hyphen (-) is to join two words — for example ‘front-end’ — and to separate syllables when splitting a long word over two lines. As previously mentioned, the hyphen is often misused in place of both the above.

The minus

There is also a seperate dash for the minus symbol. The proper entity for a minus symbol is simply −.

Reader Comments:

“Nice, didn’t realise there was so much variety with a dash. Something I’ll bear in mind. Thanks.” liam

“I know what you mean Harry, You ARE a geek :D” Joe Whitley

“Nice Thanks” ket

“@liam: I was the same, but now I can spot an em dash at 20 paces.
@Joe: I know
@ket: You’re welcome.” Harry Roberts

“The language geek in me squealed in delight at this article.” m

“There’s far more than three dashes :)
http://garyjones.co.uk/development/hyphens (the majority of which is accredited to an article on A List Apart).” Gary

CSS Wizardry The Three Types of Dash

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