ASD-STE100 Simplified Technical English

English is the most common language for technical documentation. Yet, most of the world’s technical workforce – from engineers to technicians – are non-native English speakers. Even native speakers struggle with long sentences, vague words, and inconsistent terminology. 

That’s where ASD-STE100 comes in. It’s a controlled natural language (CNL) – with approved words and clear rules – designed to make technical writing simple, safe, and reliable. 

ASD-STE 100 is: 

• A standardised vocabulary: only approved words, each with one meaning.
• Clear writing rules: active voice, short sentences, logical structure.
• Global adoption: used in aviation, defence, and industrial documentation.
• Maintained by experts: developed and updated by the STEMG – an ASD group of engineers, linguists, and technical authors.

Trusted standard from aviation to manufacturing 

STE was created in the 1980s by the European aerospace industry to improve the clarity of maintenance manuals in aviation. Over time, its use expanded into defence, rail, automotive, oil & gas, IT, medical devices, and many other safety-critical sectors. 

Whether you're writing aircraft maintenance manuals or machinery user guides, Simplified Technical English (STE) helps eliminate ambiguity and improve understanding in technical documentation. 

Today, STE is recognised as a global standard for improving: 

• Clarity and consistency. 
• Translation efficiency.
• Safety and operational accuracy.