Simplified Technical English (ASD-STE100)

Simplified Technical English (STE) is a controlled language for technical documentation. It exists so that procedures, manuals, and warnings can be read the same way by every reader — including non-native English speakers. Its two halves are a set of writing rules and a controlled vocabulary (one word, one meaning, one part of speech).

Use this skill to do one of two jobs — ask which if it is unclear:

• Rewrite — turn source text into STE.
• Check — flag violations in existing text and explain each one.

STE is designed for procedures, descriptions, warnings, and cautions. It is not for marketing copy, narrative prose, or legal text — say so if asked to apply it there.

The rules that matter most

Apply these in order. The first four fix the majority of problems.

1. One idea per sentence. For procedures, write one instruction per sentence. Split compound instructions into separate steps.
2. Keep sentences short. Procedural sentences: 20 words max. Descriptive sentences: 25 words max. Paragraphs: 6 sentences max.
3. Use the active voice. In procedures, use the imperative ("Open the valve"), not the passive ("The valve should be opened").
4. Use simple verb tenses. Present, past, or future only. Avoid the -ing form (no present participle / gerund) and avoid perfect tenses.
5. One word, one meaning. Use the same word for the same thing every time. Do not use synonyms for variety ("start" everywhere, never also "initiate", "activate", "begin"). Do not use one word for two meanings.
6. Keep the articles and connectors. Do not drop the, a, that, or which to save words. They prevent ambiguity ("Remove displays" → "Remove the displays").
7. Prefer short, common, approved words. Choose the simplest word that works: "use" not "utilize", "about" not "approximately", "do" not "perform", "before" not "prior to".
8. Be specific — no vague pronouns or noun clusters. Avoid strings of three or more nouns ("runway light connection resistance"). Break them up with prepositions. Replace vague "it"/"this" with the actual noun.
9. Warnings and cautions first. Put the safety instruction (the command) first, then the reason: "Do not touch the wire. It is live." not "Because the wire is live, you must not touch it."
10. Use lists for conditions and sequences. When several conditions or steps pile up in one sentence, break them into a vertical list.

Rewrite workflow

1. Read for intent — know what the text tells the reader to do or know.
2. Split — one sentence per instruction or per fact.
3. Convert to imperative / active for every instruction.
4. Shorten — cut fillers, fix tense, drop -ing, respect the word limit.
5. Normalize terms — pick one term per concept and use it throughout.
6. Reorder warnings — command first, reason second.
7. Re-read as a non-native speaker — anything ambiguous gets rewritten.

Preserve the source's technical meaning exactly. If simplifying would change or drop a technical detail, keep the detail and flag the tension instead.

Check workflow

When asked to check (not rewrite), report each issue as:

[line/quote] — <rule broken> — <why it's a problem> — <suggested fix>

Group by severity: ambiguity and safety issues first, then readability. Do not rewrite the whole text unless asked; give targeted fixes.

Examples

Wordy passive → imperative, split, shortened

• ✗ "It should be ensured that the power supply has been disconnected before any attempt is made to remove the cover, as failure to do so may result in a risk of electric shock."
• ✓ "Warning: Electric shock can kill you. Disconnect the power supply. Then remove the cover."

Synonyms and vague terms → consistent, specific

• ✗ "Initiate the pump, then verify the unit is operational and monitor it."
• ✓ "Start the pump. Make sure that the pump operates. Look at the pump."

Noun cluster → prepositions

• ✗ "Check the runway light connection resistance value."
• ✓ "Check the resistance of the connection for the runway light."

Dropped articles → restored

• ✗ "Remove access panel and disconnect battery cable."
• ✓ "Remove the access panel. Disconnect the battery cable."

Notes and limits

• The official ASD-STE100 dictionary of approved words is copyrighted and not reproduced here. Apply the principles above; when in doubt, choose the simplest common English word and use it consistently.
• STE limits vocabulary on purpose. If a needed technical name or technical verb is not a "plain" word (e.g. "calibrate", "solder"), that is allowed — STE permits approved technical terms. Do not dumb these down.
• When you finish a rewrite, offer a short note of what changed (e.g. "split into 4 steps, removed passive voice, standardized 'start'").