The em dash is perhaps the most versatile punctuation mark. Depending on the context, the em dash can take the place of commas, parentheses, or colons—in each case to slightly different effect. Notwithstanding its versatility, the em dash is best limited to two appearances per sentence. Otherwise, confusion rather than clarity is likely to result. Do not mistake the em dash (—) for the slightly narrower en dash (–) or the even narrower hyphen (-).