# ASD-STE100 Simplified Technical English
ASD-STE100 (Simplified Technical English) is a controlled-language standard from the aerospace industry, first published in the 1980s: 53 writing rules plus a restricted dictionary where each word has ONE approved meaning. It was designed for maintenance manuals whose readers might die if a sentence is ambiguous. Short sentences, active voice, one instruction per sentence, no synonyms.
It resurfaced in 2026 through an unexpected door: people started packaging STE as an [[AI Agent Skills|AI Agent Skill]] to "force" [[Large Language Models (LLMs)]] to write documentation in it. The version that hit the Hacker News front page (AminBlg/SimpleEnglish) makes Claude apply the STE rules to everything it writes. The appeal is obvious: LLMs default to long, verbose, hedge-everything prose, and a strict rulebook is exactly the kind of constraint they follow well. The AI skill's own README shows classic LLM writing tells, which is a funny look for a writing-quality tool.
The underlying standard predates all of this by four decades, though, and the core idea stands: **constraining vocabulary and grammar removes ambiguity, for human readers and machine readers alike**.
## References
- GitHub (agent skill): https://github.com/AminBlg/SimpleEnglish
- Hacker News discussion: https://news.ycombinator.com/item?id=49114639
- Official STE site: https://www.asd-ste100.org/
## Related
- [[Claude Code Skills]]
- [[Claude Code]]
- [[Hallmark]]