There's a recent trio of pieces in the Economist's column on language, Johnson, that should be of interest to lawyers, as they all revolve around that tricky word "shall." The fuss started when Robert Lane Greene, who edits the column and writes as R.L.G., praised the US government's Federal Plain Language Guidelines [PDF] for recommending that writers drop "shall" and calling it that "officious and obsolete [word] that has encumbered legal style writing for many years." That column racked up fifty comments, not all of them approving.
A day later, R.L.G. took another crack at the "shall," in the light of this criticism. Most of his response had to do with differences between US and British usage, principally the use of "shall" to indicate futurity in the first person: I shall call tomorrow; you will hear from me. As with any aspect of usage, his discriptivist approach made a prescriptivist rule dissolve away — though, these two attitudes towards usage address quite different domains, in my view, and to pit them against each other is a kind of category mistake. But I digress.
Greene's third sally against "shall" took place squarely in the legal domain, where he prayed in aid Bryan Garner's 2001 edition of the Dictionary of Modern Legal Usage. Both, essentially, point out how difficult that word is in a legal context, mostly, but not always, conveying obligation. And it's the "not always" that's the problem, of course. Greene has Garner conclude that "this word is so confusing, even to many very clever people, that the alternatives are better."
Garner's own words (p. 940) put it this way:
One solution to the problem that shall poses is to restrict it to one sense. This solution—called the “American rule” because it is an approach followed by some careful American drafters—is to use shall only to mean “has a duty to.” Under the American rule, only the first of the eight bulleted items above would be correct. The drafter might well say that a party shall send notice, but not that notice shall be sent by the party. (If this “has-a-duty-to” sense is the drafter’s convention, must serves when the subject of the sentence is an inanimate object.) This solution leads to much greater consistency than is generally found in American drafting.
Another solution is the “ABC rule," so called because, in the late 1980s, it was most strongly advocated by certain Australian, British, and Canadian drafters. The ABC rule holds that legal drafters cannot be trusted to use the word shall under any circumstances. Under this view, lawyers are not educable on the subject of shall, so the only solution is complete abstinence. As a result, the drafter must always choose a more appropriate word: must, may, will, is entitled to, or some other expression.
This view has much to be said for it. American lawyers and judges who try to restrict shall to the sense “has a duty to" find it difficult to apply the convention consistently. Indeed, few lawyers have the semantic acuity to identify correct and incorrect shalls even after a few hours of study. That being so, there can hardly be much hope of the profession’s using shall consistently.
Small wonder, then, that the ABC rule has fast been gaining ground in the U.S. For example, the federal government’s Style Subcommittee—part of the Standing Committee on Rules of Practice and Procedure—a subcommittee that since 1991 has worked on all amendments to the various sets of federal court rules, adopted this approach, disallowing shall, in late 1992. (This came after a year of using shall only to impose a duty on the subject of the verb.) As a result, the rules have become sharper because the drafters are invariably forced into thinking more clearly and specifically about meaning.
Whatever your personal drafting preferences, the Johnson column, the US PLAIN guidelines, and, of course, Garner's book are valuable reads. I won't say you must read them, but I think you ought to.