ASD-STE100 Simplified Technical English (STE) is a controlled language designed to simplify and clarify technical documentation. It was originally developed during the 1980's by the European Association of Aerospace Industries (AECMA), at the request of the European Airline industry, who wanted a standardized form of English for technical documentation that could be easily understood by non-English speakers. It has since been adopted in many other fields outside the aerospace, defense, and maintenance domains for its clear, consistent, and comprehensive nature. The current edition of the STE Specification, published in April 2021, consists of 53 writing rules and a dictionary of approximately 900 approved words.