Claude Code skill · Research notes

STE: make the model write like a maintenance manual

A Claude Code skill that holds generated documentation to ASD-STE100 Simplified Technical English, the aerospace controlled language. This page has the skill, the install command, and the research notes behind it.

Where this came from

A @geogristle post (July 18, 2026, 2.2M views): “You can get LLMs to write good non-AI-slop-sounding technical documentation by requiring them to adhere to ADS-STE100 Simplified Technical English.” The author corrected the typo in a reply (“ASD whoops”). The standard is ASD-STE100, from ASD (AeroSpace and Defence Industries Association of Europe, the trade body that maintains the spec).

What ASD-STE100 is

STE (Simplified Technical English) is a controlled language: a deliberately restricted subset of English in which each construction has one reading. European airlines asked for it in the late 1970s because their mechanics, mostly non-native English speakers, had to work from manuals written in loose idiomatic English. AECMA (the European Association of Aerospace Industries, ASD’s predecessor) published the first guide in 1986. STEMG (the Simplified Technical English Maintenance Group) has maintained it since. The current edition is Issue 9, published January 2025, and the spec is free on request from asd-ste100.org.

The standard has two parts:

Part 1: 53 writing rules in 9 sections covering word choice, grammar, sentence structure, and style.
Part 2: a controlled dictionary of about 900 approved words. Each word gets exactly one meaning and one part of speech. About 1,200 unapproved words are listed with approved alternatives.

Two examples of how strict the dictionary is. close is a verb only, with two approved meanings: move things together, or operate a circuit breaker. You can close a door but not a meeting. oil is a noun only: “the oil is dirty” passes, “oil the valve” fails.

The rules that do the work

Rule	Limit
Procedural sentence length	20 words, one instruction per sentence
Descriptive sentence length	25 words
Paragraph	One topic, 6 sentences max, topic sentence first
Verb forms	Imperative, simple present/past/future, infinitive, past participle as adjective. No present perfect, no `-ing` verb forms, no auxiliary pileups.
Voice	Active. Passive only in description when the agent is unknown.
Noun clusters	3 words max
Vocabulary	One word, one meaning, one part of speech. No synonym rotation.
Warnings	Before the step, phrased as a command, no hedging

Technical names are exempt. Commands, API (Application Programming Interface, the callable surface of a program) names, error strings, and domain terms stay verbatim. STE controls the connecting language, not the terminology.

Why this kills AI slop

The tells of AI-generated prose are, almost line for line, STE rule violations. Hedging stacks (“could potentially lead to”) break the warning rules. Synonym rotation breaks one-word-one-meaning. “Furthermore” and “it is worth noting that” are unapproved words. Present-perfect padding (“has been designed to provide”) breaks the tense rules. Forty-word sentences break the length caps. You do not have to tell the model “don’t sound like AI,” which it cannot act on. You give it 53 checkable rules, which it can.

Example rewrite

Before · 41 words Before proceeding with the deployment process, it is important to ensure that all of the required environment variables have been properly configured, as failing to do so could potentially result in the application encountering unexpected runtime errors. After · STE Make sure that all required environment variables are set before you deploy. If a variable is missing, the application will fail at runtime.

The skill

The skill has two modes. Write: produce or rewrite documentation in STE. Audit: check an existing document and return a violations table with suggested rewrites. It bundles a replacement table for the unapproved words that show up most in software docs (utilize→use, ensure→make sure that, prior to→before, leverage→use).

Two additions from field reports:

The standard is invisible. Early users found their agents stamped every document with “written to ASD-STE100 but not certified.” The skill now forbids this. STE is how the agent writes, not a fact about the document. The reader should only notice that the text is clear.
Document shape. The skill folds in the document-level rules from ayghri/i-have-adhd (MIT): start a how-to with the first action, number every procedure, cap lists at five, put prerequisites before step 1, end with the check that proves it worked. STE fixes the sentences; these rules fix the document.

Install (Claude Code)

mkdir -p ~/.claude/skills/ste/references
curl -fsSL https://ste-skill.matthias-4ff.workers.dev/skill/SKILL.md -o ~/.claude/skills/ste/SKILL.md
curl -fsSL https://ste-skill.matthias-4ff.workers.dev/skill/references/word-choices.md -o ~/.claude/skills/ste/references/word-choices.md

Then say /ste, or ask for docs “in simplified technical english,” or “audit this README against STE.”

Optional companion, the full i-have-adhd output style (shapes chat responses, not documents; it stays a separate skill because it is a session mode with its own on/off switch):

mkdir -p ~/.claude/skills/i-have-adhd
curl -fsSL https://ste-skill.matthias-4ff.workers.dev/i-have-adhd/SKILL.md -o ~/.claude/skills/i-have-adhd/SKILL.md

Files

skill/SKILL.md the skill: rules digest, document shape, modes
skill/references/word-choices.md unapproved → approved replacement table
i-have-adhd/SKILL.md companion output style, mirrored from ayghri/i-have-adhd (MIT)

Sources

asd-ste100.org — official site, free spec (Issue 9, Jan 2025)
asd-europe.org — ASD’s page on the standard
Wikipedia: Simplified Technical English — history, rule summary
TechScribe — worked examples of approved vs unapproved usage
SKYbrary — aviation-safety view of STE

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