Vagueness and Clarity in And/Or

An interesting blog post that I once read decried the use of and/or. The author makes the case that the conjunction is inaccurate. This, at least, is an improvement over the popular argument that and/or is “hideous” or “monstrous,” but it isn’t entirely true, either.

Vague from the Start

And/or was first used in the 19th century in legal texts and by 1854 its use in contracts was being challenged in court as being vague. While one party could assume one meaning of and/or, the other party could assume a second, more advantageous meaning. Since then, many people, especially those in the legal profession, have called out against its use.

Criticism of and/or is frequently reduced to name-calling, however. Samuel Hardin Church seems to have been one of the first to get personal by calling the conjunction “a hideous invention” in 1920. Since then, many others have added their dislike to the chorus. Theodore Bernstein, author of The Careful Writer, called it “a visual and mental monstrosity.” Others have simply called it “ugly.”

When critics resort to aesthetics, they have no foundation for their dislike other than personal taste. While having personal dislikes is fine, advising others to follow suit is worthless. Writers and editors would be wise to ignore such advice.

Critics who challenge and/or’s clarity have a good case. It essentially lays out three (or more) choices without actually making a choice. So if you are at a birthday party and say, “I’ll have cake and/or ice cream, please,” you’re saying you’ll have cake, ice cream, or both. You haven’t made a decision, which is probably unwise when the server is holding a cake knife in their hand.

Look around and you’ll find no shortage of vague or inaccurate and/or usages. In particular are situations where the options offered are mutually exclusive:

This follows given the significant finding that teachers in schools with a higher percentage of students who receive free and/or reduced lunch are more likely to have interactive whiteboards in their classroom.

Journal of Instructional Psychology, September 2011

One student cannot receive a hot lunch both for free and at a reduced cost. It’s one option or the other. A group can be made up of students who receive free lunches and students who receive reduced-cost lunches, however. In this case, or alone would do the job and simplify the sentence:

A higher percentage of students who receive free or reduced lunch are more likely to have interactive whiteboards in their classroom.

And/or Has Its Moments

That said, sometimes and/or is accurate. You can lay out three choices for the reader to choose from: A, B, or both. Though style guides are among those resources that generally disparage and/or, at least couple use it, and do so correctly (note: they are published by the same company):

A list of errata should be as concise as possible, making clear the location, the substance of the error, and the form of the correction. Italic type is used for editorial directions, and punctuation is included only where it is part of the error and/or the correction.

New Hart’s Rules, 2005

The name of each enzyme consists of an italic three-letter prefix plus an identifying letter and/or numbers (no intervening spaces).

New Oxford Dictionary for Scientific Writers and Editors, 2009

In the first example, a list of errata should not use punctuation unless it is part of the error, part of the correction, or both. In the second example, the enzyme’s name could include an identifying letter, identifying numbers, or both.

Certainly the writers could have simply said the equivalent of “A, B, or both.” But the meaning is just as clear and precise with “A and/or B.”

When and Where to Use It

Despite over a hundred years of advice against using and/or, English speakers and writers are clearly attached to it. A Google Books search returns about 455 million results for 2000 through 2023. A search in the Corpus of Contemporary American English shows that academics have a fondness for this conjunction, and Google News demonstrates that journalists aren’t afraid of it, either.

The trick to using and/or is the same as it is for any usage: you need to use it both correctly and for an audience that will accept it.

And/or is fine for detailing three choices, as long as all three choices are possible and acceptable. When a choice needs to be made, though, and/or is a weaselly solution; it avoids making a choice at all.

And/or is generally acceptable in academic and business writing but discouraged in fiction and tech writing. Be wary of it in legal writing, as well. Despite its popularity there, the consequences of misinterpreting and/or could be costly.

A version of this article originally published on March 18, 2013 on Visual Thesaurus.