Various issues regarding the drafting of instruments
General
  1. When considering the use of the expression "and/or", drafters need to clarify the scope of each of the coordinating conjunctions "and" and "or" when used separately.
  1. The conjunction "and" on its own poses no particular problem of interpretation. Its purpose is to link two parts of a phrase and expresses the idea of addition. In a legal instrument defining the conditions that must be met for a right or an obligation to take effect, the word "and" indicates that the conditions in question are cumulative and must all be met.
  1. The conjunction "or" is a little more ambiguous. In principle, the term is inclusive in meaning, but can have an exclusive connotation;[398] depending on the context. On the one hand, it may thus indicate either that all the conditions or that only some of them must be met (inclusive use). On the other hand, it may also convey the idea that one - and only one - of the stated conditions must be met (exclusive use of "or" indicating alternative conditions). This applies, for example, to cases where the conjunction "or" links mutually exclusive conditions which cannot coexist without giving rise to a contradiction in terms or a practical impossibility.
  1. The use of the expression "and/or" in some technical writing, including legal texts, is intended to prevent the conjunction "or" from being construed in its exclusive (disjunctive) sense. It is not clear that this phrase eliminates ambiguity. Judge Louis-Philippe Pigeon, a former Justice of Canada's Supreme Court, once wrote when Professor of Constitutional Law:
  • What is to be said of "and/or"? It is quite simply inadmissible. I quote part of what Daviault said in his work Langage et traduction regarding "and/or": he cites a United States judge who described the combination as "A befuddling, nameless thing, that Janus-faced verbal monstrosity, neither word nor phrase, the child of a brain of someone too lazy or too dull to know what he means."
  • "And/or" appears to be used by people whose main concern is to appear erudite. In my view, they achieve quite the opposite effect. Use of this pseudo-conjunction is abhorrent to the spirit of both English and French. It is important to take the time to think and to construct a sentence in such a way as to avoid
    it.[399]
[398] That is, the conditions cannot be cumulative.
[399] Pigeon, L.-P.: Rédaction et interprétation des lois, 2nd edition (Quebec, Editeur officiel du Québec, 1978), p. 35.