Simplified Technical English

Purpose

Write technical content that is accurate, direct, consistent, and difficult to misunderstand. This compact guide is based on ASD-STE100 Issue 9. It does not replace the official standard or controlled dictionary.

Priorities

1. Preserve technical meaning and safety.
2. Remove ambiguity.
3. Use consistent terminology.
4. Reduce length only when clarity remains intact.

Reference routing

• Read rule-navigation.md when an exact rule location, more context, or strict compliance matters.
• Read examples.md when you need before-and-after patterns for a revision or explanation.
• Treat both references as aids. For strict compliance, check the official PDF, its controlled dictionary, and the applicable terminology database.

Vocabulary

• Use approved STE words when the dictionary is available.
• Use each approved word only with its approved meaning, part of speech, and form.
• Use necessary technical nouns and verbs accepted by the relevant organization or field.
• Use one term for one item. Do not alternate between synonyms.
• Avoid slang, jargon, regional wording, idioms, and phrasal verbs.
• Use American English spelling unless an official requirement specifies otherwise.
• Rewrite the sentence when a word-for-word substitution is not clear.

Nouns

• Keep multi-word nouns to three words or fewer.
• When an official term is longer, write it in full first. Then define a clear short form or use hyphens to mark words that function as one unit.
• Prefer prepositions or relative clauses to long noun stacks.
• Use a, an, the, this, or these where needed.

Verbs

• Use active voice and name the actor.
• Use a verb to express an action, not an abstract noun phrase.
• Use only the infinitive, imperative, simple present, simple past, simple future, and permitted past-participle forms.
• Avoid complex auxiliary constructions.
• In descriptive text, use passive voice only when the actor is unknown.
• Use an -ing form only as an accepted technical noun or modifier in a technical noun.

Sentences and lists

• Write complete, direct sentences. Do not use contractions or omit necessary words.
• Put one main idea in each sentence.
• Use a vertical list for several conditions, items, or actions.
• Use explicit connecting words when the relation between sentences is not clear.
• Do not use semicolons.

Procedures

• Use no more than 20 words in a sentence.
• Put one instruction in each sentence, except when actions occur simultaneously.
• Begin an instruction with an imperative verb: Remove, Install, Measure.
• Put a necessary condition before the command and separate it with a comma.
• Use notes for information only. Do not put instructions in notes.

Descriptions

• Use no more than 25 words in a sentence.
• Give information gradually, from general context to specific detail.
• Give each paragraph one topic and no more than six sentences.
• Repeat key terms when repetition prevents ambiguity.

Safety instructions

• Identify the risk level with the approved signal word or symbol.
• In ASD usage, a warning identifies risk of injury or death. A caution identifies risk of damage to objects.
• Start with a clear command or condition.
• State the hazard or possible result explicitly.

Final check

Confirm that:

• each instruction has one clear action.
• each pronoun has one clear referent.
• each item has one consistent name.
• sentence and paragraph limits are met.
• safety consequences are explicit.
• units, identifiers, labels, quotations, and technical facts are unchanged.
• no simplification creates ambiguity.

For strict compliance, check every general word against the official dictionary and every technical term against the applicable terminology database.

Source and boundary

This skill is an operational digest. It states the rules in our own words, and it carries no part of the standard large enough to replace it. Read the official document for the complete rule, its explanation, and its dictionary entries.

Standard: ASD-STE100 Simplified Technical English, Issue 9 (2025)

Every statement above is accounted for in a public trace. Each one either cites a numbered rule in the standard, or is marked as our own editorial guidance, or is marked as narrative that asserts no rule. The trace lives in the stylewright repository. It is not installed with this skill, because it is an audit record for a reader and not context for an agent.

Notice

This skill is not affiliated with, endorsed by, or approved by ASD. ASD-STE100 and Simplified Technical English are European Union registered trademarks owned by the Aerospace, Security and Defence Industries Association of Europe, number 017966390.