“A, B, and/or C”

I’d like to revisit and/or.

For the most part, there’s nothing to say about and/or other than (1) A and/or B means A or B or both, (2) and/or can create confusion and  be misused, and (3) it’s clearer to use instead the structure A or B or both. Beyond that, I don’t get worked up about and/or, as many other usages create more problems than does and/or.

But consider the following:

A, B, and/or C
one or all of A, B, and C
one or more of A, B, and C

The phrases in italics are the alternative meanings of A, B, and/or C. When you have more than two items linked by and/or, what happens is that you fall into the deep, dark hole that is uncertainty over whether the or is inclusive or exclusive. That’s something that over the years has consumed many of my brain cells. So if and/or links more than two items, it’s flat-out ambiguous.

This was pointed out to me by one of the manuscript readers sent to me by the drafting gods. I haven’t seen it discussed in the literature. Have any of you?

A good starting point for anyone delving into and/or would be this survey by Ted Tjaden.

About the author

Ken Adams is the leading authority on how to say clearly whatever you want to say in a contract. He’s author of A Manual of Style for Contract Drafting, and he offers online and in-person training around the world. He’s also chief content officer of LegalSifter, Inc., a company that combines artificial intelligence and expertise to assist with review of contracts.

16 thoughts on ““A, B, and/or C””

  1. Ken, I tend to come across this in numbered lists. If

    A. Asdf;
    B. ghjk; or
    C. Zxcv

    Can mean any of a,b,c. And

    A. Asdf;
    B. ghjk; and
    C. Zxcv

    Means all of a,b,c

    Doesn’t it follow that

    A. Asdf;
    B. ghjk; and/or
    C. Zxcv
    Means any or all of the bove?

    • Mark: With the benefit of a good night’s sleep, and your comment to prod me, I realized that of course it’s not clear whether the “or” is inclusive or exclusive; I’ve revised the post accordingly. A good chunk of MSCD is devoted to that topic. Ken

  2. Ken, I like your third alternative (“one or more of A, B, and C”) as a substitute for the term and/or when dealing with a list of three or more items, not least because your point about the potential for ambiguity in such a list is worth considering.

    It does seem, though, that the critic’s objection to and/or typically boils down to “because I don’t like it.” The term is a perfectly serviceable shorthand that, I would argue, is well-understood as referring to the non-exclusive or — in mathematical terms, OR as opposed to XOR.

    • Non-native English speakers are often confused by “and/or,” it can be used inappropriately to link items that can’t be alternatives, and “A or B or both” is clearer. So I’ve moved on from “and/or” without any qualms.

  3. Two points:

    1/ Ted Tjaden’s survey is very impressive.

    2/ Couldn’t “A, B, and/or C” have the following third meaning: “A plus either B or C”?

  4. The Elements of Style by Strunk & White (4th Ed.) provides at page 40:

    And/or. A device, or shortcut, that damages a sentence and often leads to confusion or ambiguity.

    Strunk & White then provide these two examples:

    First of all, would an honor system successfully cut down on the amount of stealing and/or cheating?

    First of all, would an honor system reduce the incidence of stealing or cheating or both?

  5. Would “any one or combination of A, B, or C” remove the ambiguity?
    – Just a 2L trying to learn how to draft better contracts.

      • Ken:

        Thank you for the quick response. I realized “one or more” as soon as I posted, but I could not find a way to delete my comment.

        After a day of studying for finals I was not thinking clearly.

        I appreciate the time you spend on the blog. My school does not offer a formal drafting class, and your blog has been a helpful resource as I try to learn through my own efforts.


  6. “That abominable combination of the conjunctive and disjunctive!”

    That quote makes me smile. I wish I could cite the judge. I came across it in Adam Freedman’s “Party of the First Part.”

    Freedman also mentions a 1936 TX Appeals court overturning a gambling conviction because the indictment ambiguously charged the defendant with wagering on “cards, dice and/or dominoes.”

    • Friedman concludes: “Apart from sodomy, it would be difficult to find any practice that has inspired more judges to use the word abomination.”

      Spot on. Tjaden repeats the word “abomination” 3 times.

  7. It is very slightly ambiguous in this one specific construction, but it is still far less ambiguous than ‘or’ would have been, and significantly more concise than ‘one or more of A, B, and C’. I have a hard time imagining anyone actually interpreting it to mean ‘either one or all of A, B and C’.


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