Punctuation is vital to written communication. It creates the pauses, inflections, hand gestures and body language of the written word. If punctuation is not used well, typographic communication can be confusing, misleading, and difficult to read. There are some times, however, that punctuation can also be disruptive to the communication process – even if it is used properly.

Dashes and hyphens are often confused but are not interchangeable.

Hyphens are used to divide words that break at the end of a line and to connect parts of compound words such as go-between, ill-fated and run-of-the-mill.

En Dashes are used to indicate a range of almost anything with numbers, including dates, times and pages in a document. Please refer to the Chicago Manual of Style, pps 187–188.

Em Dashes are used for emphasis. Since they break up the flow of the sentence—only use the em dash to stress a point. An em dash can also indicate missing words or a sudden break in thought—confusing, isn't it?

The problem with Em dashes is that they make such a strong statement. They can, in fact, be troublesome in text copy – stopping the reading flow altogether. A friend who lives on the other side of the United States recently told me about a particularly loud and obnoxious person in her design community. He always disrupts conversations and discussions with vociferous blurts and interruptions. He thinks that his interjections are more important than the surrounding dialogue. She calls him "Em Dash."

Apparently not much can be done to change the behavior of this person. I've found, however, that emphasis can be indicated in sentences by using a punctuation mark that isn't so noisy and disruptive. Sometimes – if space is added on either side – an en dash can be used in place of an em dash. Some style manuals support this idea—others don't. If you want to try this copy-calmer, be sure that you are in sync with the style required by your client.

Allan Haley is Director of Words & Letters at Monotype Imaging. Here he is responsible for strategic planning and creative implementation of just about everything related to typeface designs.