In August 2025, ISO (the International Organization for Standardization) published ISO 24495-2:2025 (Plain language — Part 2: Legal communication). Here’s how ISO describes ISO 24495-2:
This document deals with legal communication, and it builds on the foundation for plain language in ISO 24495-1. It establishes guidelines and techniques to help authors make sure that readers can readily understand legal communication and exercise their legal rights and obligations.
In this LinkedIn post from September 2025, I said I planned on ignoring ISO 24495-2. Then last week a friend sent me a link to this post on Contract Nerds. It’s entitled The End of Fine Print: Lessons from ISO 24495-2 on Plain Legal Language. It’s effusive. Here’s the opening paragraph: “For too long, legalese has been the default because ‘that’s how it’s always been done.’ But ISO 24495-2 shifts the ground beneath our feet. Clarity is now the global benchmark.” Similarly enthusiastic is this post on Legal Creatives, entitled Plain Language in the Law Is No Longer Optional: ISO Just Set the Standard.
With a shrug, I decided that if people are going to get excited about ISO 24495-2, I should probably get a copy. So I did. I paid 98 Swiss francs, otherwise known as US$122. In return I got a PDF that consists of six pages of front matter (including one page for the cover, one page for a formulaic ISO foreword, one page for a half-page introduction, and a blank page), eight pages of main text, and five pages of annexes. In total, 19 skimpy pages.
It Offers Nothing of Real Value
Something that short can’t tell you anything useful. The main text offers platitudes on topics that feature routinely in the substantial literature on legal writing. “Authors should not leave out any content that readers need to know.” “Write clear sentences.” And so on. And it offers only token examples.
Learning to write clearly requires getting to grips with lots of information—platitudes without details get you nowhere. Compare ISO 24495-2 to the US Securities and Exchange Commission’s publication A Plain English Handbook, which is free and weighs in at 77 pages, with a decent amount of detail.
ISO 24495-2 aims to be relevant for almost all kinds of legal writing, including court opinions, statutes, and contracts. If ISO 24495-2 had addressed just one kind of legal writing, it might have provided relevant advice, and it might have provided some detail. But that would have required real work. Nothing in ISO 24495-2 suggests that those responsible for ISO 24495-2—Technical Committee ISO/TC 37, Language and terminology—are up for that.
The Writing Is Clumsy
ISO 24495-2 has all the charms of a technical manual. It’s unfortunate that a document intended to promote clear writing is itself clumsy.
Here’s just one example, from page 7: “However, graphic formats help readers understand complex ideas or text structures.” Like many other sentences, it’s a little off. “Graphic formats”? “Text structures”?
This document contains a few sentences from ISO 24495-2 and how I would rewrite them. My changes might not be optimal, but I’m confident they’re an improvement.
It Gets Technical Stuff Wrong
Legal writing raises issues that go beyond the usual challenge of making regular prose clear. I spotted seven examples of ISO 24495-2 getting wrong, or missing, something technical.
First, it could have handled better how it uses defined terms. It contains half a page of definitions; one of those definitions is of the term legal document. From the definition, I learned that ISO 24495-2 apparently doesn’t cover submissions written by parties to dispute-resolution proceedings. Instead of burying that nuance in a definition, I would have said in the introduction what kinds of writing are covered. (Incidentally, excluding dispute-resolution submissions seems odd. They’re clearly legal, and they’re analogous to judicial and tribunal decisions.)
Second, page 3 recommends using “layering” to “present information that suits different readers in the same document,” for example in separate columns or separate sections. That conflicts with one of my list of characteristics of optimal contract language, namely that contracts shouldn’t say the same thing twice. See A Manual of Style for Contract Drafting (MSCD) § 1.56. Saying the same thing in different ways invites a dispute over which way prevails. At a minimum, it would have been prudent for ISO 24495-2 to acknowledge that risk.
Third, page 6 says, “Inform the reader of any specific meaning in some legal or technical contexts.” As an example, it offers this: “Modal verbs such as ‘shall’, ‘must’, ‘will’ and ‘may’ imply distinct obligations, promises, rights or choices.” This sort of internal rule of interpretation is always a bad idea. See MSCD §§ 15.21, 15.22 (5th ed. 2023). And this example is particularly confusing.
Fourth, page 7 offers guidelines on vagueness. But the examples it offers don’t involve vagueness. As MSCD says at § 7.46, “Vagueness is a function of there being no clear demarcation between, say, being prompt and not being prompt.” What ISO 24495-2 refers to isn’t vagueness, it’s not being specific. That’s entirely different.
Fifth, page 8 offers guidelines on ambiguity. One kind of ambiguity that’s described is what ISO 24495-2 calls “patent contextual ambiguity.” Black’s Law Dictionary says patent ambiguity is “An ambiguity that clearly appears on the face of a document, arising from the language itself.” But the example offered isn’t an instance of ambiguity, in other words a word or phrase having alternative possible meanings. Instead, it’s an example of a different kind of uncertainty—conflict. See MSCD § 7.37.
Sixth, page 8 also refers to another kind of ambiguity, “latent contextual ambiguity.” Black’s Law Dictionary defines latent ambiguity as “An ambiguity that does not readily appear in the language of a document, but instead arises from a collateral matter once the document’s terms are applied or executed,” and it alludes to the famous case of Raffles v. Wichelhaus. That’s not what’s on display in the example of this ambiguity offered on page 8. Instead, MSCD addresses that kind of uncertainty in a section entitled “Avoiding Confusion by Adding a Time Component.” See MSCD § 10.152. (Incidentally, MSCD doesn’t use the term “latent ambiguity”—the confusion in Raffles v. Wichelhaus is due to mistake. See MSCD § 7.35.)
Any seventh, ISO 24495-2 doesn’t mention an important kind of ambiguity, that relating to plural nouns and the words and, or, each, all, any, and every. I call it “ambiguity of the part versus the whole.” See MSCD chapter 11.
The Price Is a Rip-Off, and It’s Self-Defeating
Nothing can justify charging 98 Swiss francs for something as skimpy as ISO 24495-2. That exorbitant price might result in most of the world doing what I had been inclined to do—ignore ISO 24495-2.
Implications for ISO Certification
Companies can have an independent body certify that it has complied with an ISO standard. According to ISO, “Certification can be a useful tool to add credibility, by demonstrating that your product or service meets the expectations of your customers.” But it’s hard to imagine that working in the case of ISO 24495-2, given how slight and problematic it is.
