There is a version of English with about nine hundred permitted words. It was built so that a mechanic can read a repair instruction written on another continent, in a language that is not his, and not have to guess.
October 2026
Simplified Technical English (STE), officially known as ASD-STE100, is an international standard for writing clear, unambiguous technical content.
ASD, the body that maintains the standard
It is the dullest sentence in aviation and it describes something no style guide has ever managed. In 1983 the European aerospace industry went looking for a controlled language and could not find one that fitted; by 1985 it had written its own. The airlines had asked for it. Their maintenance manuals were written in English and read by people for whom English was a second or third language, and in that trade a sentence that can be read two ways is not an infelicity. It is a grounded aircraft, or worse.
It still exists. After a merger of industry associations in 2004 it was renamed ASD-STE100, and the current edition, issue 9, came out in January 2025 with fifty-three writing rules and a dictionary of roughly nine hundred approved words. Forty years on, a thing invented for aircraft maintenance is one of the few places where the question “is this writing clear?” has an answer you can check rather than argue about.
How you shrink a language
The trick is not the small dictionary. It is what the dictionary does to each word: an approved word is approved for one meaning, in one part of speech. A word that can be a noun and a verb has to pick. A word with two senses loses one of them, and the writer who wants the second sense has to go and find a different approved word for it.
Around that sit the rules you would expect and resent: active voice, one instruction to a sentence, as few words as will carry it, no synonyms kept for variety. The effect on a page is immediate and slightly unsettling. It reads flat. There is no music in it at all, and that is deliberate — the reader is not there for music, he is under a wing with a torch.
It is also hard to write. Experienced writers dislike it most, because the rules disrupt exactly the automatic sentence-making that made them good, and because you cannot tell by eye whether a sentence complies. In practice you need a checker, and you need training, and both of those are why controlled language stayed in the industries that could cost out the alternative: aerospace first, then defence, and the parts of government, finance and law where the documentation was already feared.
What a website can take, and what it cannot
Almost nobody should write a website in Simplified Technical English. A nine-hundred-word dictionary for a page that is trying to sound like a person would be absurd, and the flatness that is a virtue under a wing is a liability on a home page.
But three of its habits transfer completely, cost nothing, and are almost never done. That is the part worth stealing.
That is the thinking. Here it is as something you can apply to a site you already have:
The habits worth stealing
- One term per thing, written down. Decide whether it is a basket, a cart or a bag, and then never use the other two. Keep the list in a file, not in your head, because the second writer who joins will not have your head.
- Kill the synonyms you kept for variety. Varying the word is a habit from essay writing, where repetition is a sin. In instructions it is a trap: the reader assumes two words mean two things and goes looking for the difference.
- One instruction to a sentence. Two actions joined with “and” is where people skip a step. Split it, number it, and let the list be as long as it honestly is.
- Say who does what. Active voice, with the actor named. “Your application will be assessed” hides the one fact the reader wants, which is who is doing it and therefore who to chase.
- Write for the reader whose English is their third language. Not by simplifying the ideas, but by dropping the idiom, the phrasal verbs and the jokes that only work in one country. A translator will thank you; so will a screen reader.
- Keep a short list of words you have banned, with the reason. Yours will be specific: the term that means two things in your client’s trade, the one their customers never use. A banned-words list is the cheapest piece of governance there is and the only one anybody actually reads.
Why aviation got there first
Among the reasons given for controlled language, one is quieter than the rest and more interesting than all of them: it reduces exposure to liability caused by vague wording. Somebody, at some point, costed out ambiguity. They worked out what an unclear sentence is worth when it goes wrong, and concluded that a dictionary and a training programme were cheaper.
On an ordinary website that sum is never done, because the cost does not land on the person who wrote the sentence. It lands on the visitor, as a wasted afternoon, a form filled in twice, a benefit not claimed, a cancellation that did not go through — and no invoice is ever issued for it. That is the only real difference between aviation documentation and the page you are about to publish. Not the stakes. The accounting.
Read the originals
The standard itself is the real source, and it is sold rather than published. The first link is the body that maintains it.
- ASD-STE100 Simplified Technical English — ASD, the aerospace and defence association that maintains the specification. What it is, what it is for, and how to get the current issue.
- Simplified Technical English — the clearest free account of the history: the 1983 search, the 1985 guide, the 2004 renaming, and what is in the rules.
- Janice (Ginny) Redish, Letting Go of the Words — 2nd edition, 2012. The unrestricted version of the same instinct, for writers who are not allowed a dictionary of nine hundred words.