Microsoft® Manual of Style, Fourth Edition

Dashes

There are two types of dashes: the em dash (—) and the en dash (–).

Em dash

The em dash (—) is based on the width of an uppercase M. It is used primarily to set off sentence elements.

Note

Do not use word spacing on either side of an em dash. If your style sheet and your publishing process support it, insert a 1/4 en space on each side of an em dash.

Use an em dash:

• To set off a parenthetical phrase that deserves more emphasis than parentheses imply. Use one em dash on each side of the phrase.

  Microsoft style

  The information in your spreadsheet—numbers, formulas, and text—is stored in cells.

• To set off a phrase or clause at the end of a sentence for emphasis. Use one em dash.

  Microsoft style

  If you are not sure about the details, look at the illustrations ...