Em Dashes


The dashes in question are long dashes (—), known as "em dashes", as opposed to hyphens (-).

English legislative counsel have been taught that the only acceptable punctuation within a provision is a comma. French legislative counsel do not have this taboo and are free to use dashes (and other punctuation) as they are used in French writing generally. From the perspective of plain language, the ordinary-usage approach should be valid for English-language legislation as well. Therefore, what is the role of the dash and does it lend itself to use in legislative drafting?


Legislative counsel should use dashes (in moderation) when doing so would clarify matters for readers.


The Canadian Style sums up the purpose of dashes rather well:

In most of its uses, the em dash is simply a substitute for a colon, semicolon or comma … Dashes give greater emphasis to parenthetic material than do commas or parentheses. If the parenthetic material contains internal punctuation or forms a complete sentence, the commas that might have been used to enclose it should be replaced by dashes or parentheses, depending on the degree of emphasis desired or the strength of the relationship to the rest of the sentence. Parentheses are generally used to enclose material more remote from the main thrust of the sentence, dashes for material more closely related[1].

Although in English the accepted typographic practice is to leave no space between the dash and the words next to it, our current software limitations make it advisable to separate the dash from its neighbours with a space — as, in fact, is the custom in French.

In standard English, mid-sentence punctuation is not restricted to commas. Dashes and parentheses both are useful in structuring sentences visually for the reader.

In order of the emphasis that different types of punctuation give to the material they enclose:

Dashes are used in more or less the same way in both French and English. French legislative counsel have been using them since the French versions of the Acts were modernized, at the time of the 1985 Statute Revision.

The Elements of Legal Writing [2] offers the Rules set out below for the use of dashes in legal drafting. Note that the examples are given in illustration of the point being made, not of the heights of fine drafting to which one might aspire. In some of them, especially those in which a long string of information separates subject from verb, the dashes make acceptable a section that should really be redrafted as two subsections.

Rule 92. Use a dash to denote a sudden break in thought.

For example:

The Director may — or, if petitioned, shall — open the books to the public.

Rule 93. Use a dash to mean "namely," "that is," "in other words," and similar explanations or elaborations.

In such instances, what follows the dash is an exhaustive list of the possibilities.

For example:

If the Minister decides to cancel a document because a person involved — the document holder, the owner or operator (or owner-operator) of any aircraft or airport for which the document was issued, or an employee of any of the above — has contravened a provision of this Act, the Minister shall send that person a notice.

Rule 94. Use a dash to enclose parenthetical material containing commas.

For example:

The officer shall make copies of the form — in duplicate in the case of yellow files, in triplicate in the case of green files and in quadruplicate in the case of blue files — and return the original, and all copies but one, to the Office of the Commissioner, storing the retained copy for six months.

Rule 95. Use a dash to precede a final summarizing clause in sentences having several elements as subject of the main clause.

For example:

A-Level officers who fail Test 16 or 17, B-Level officers who fail Test 21, C-Level officers who fail Test 25 and officers at any level who fail the St. John's Ambulance test appropriate to their level — these officers shall take the course again.

Rule 96. Use a dash to show an addition or insertion that defines or enumerates a preceding word or phrase.

This last use is expanded on by Gowers in The Complete Plain Words,[3]

[t]o introduce an explanation, amplification, paraphrase, particularisation, or correction of what immediately precedes it.

For example:

The zoo-keeper shall keep all deadly fish — piranhas, sharks, stingrays and eels — at a safe distance.