Avoid "and/or"

Eliminate this ambiguous and unsightly word from your vocabulary.

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Legal writings routinely use the expression “and/or,” which is unsightly and ambiguous. I recommend working to eliminate it from your vocabulary. To do so, it helps to understand how the expression came to exist and why it seems so useful.

The word “or” has both an inclusive and an exclusive meaning:

·      The inclusive sense of “or” means “X or Y or both.”

·      The exclusive sense of “or” means “X or Y, but not both.”

Think about parents negotiating with a child about dessert. The parents say, “You can have ice cream or a cookie,” and the child replies: “I’ll have both!” The parents intended to use the exclusive “or,” but the child chose to interpret it as the inclusive “or.”

The expression “and/or” attempts to have it both ways, and ambiguity — which occurs when a single word or expression can be interpreted in two or more equally valid ways — is never desirable in legal writing.

If you need to use the term “or” and your meaning is not clear from context, choose one of the following expressions:

·      “X or Y or both”

·      “either X or Y” or “X or Y, but not both”

·      “any one or more of the following: X, Y, or Z”

Note that there is also a less common ambiguity that arises with “and.” The statement that “X and Y shall notify the Board” can be understood as meaning that X and Y each have a duty to notify the Board, or that X and Y, acting jointly, must notify the Board. If this is a concern, adding the words each or jointly can clarify what you mean:

·      “X and Y shall each notify the Board.”

·      “X and Y shall jointly notify the Board.”

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Ryan McCarl teaches Advanced Legal Writing and researches artificial intelligence law and policy at the UCLA School of Law. He is also a partner at the law firm Rushing McCarl. You can follow him on LinkedIn and Twitter as well as his personal blog.