The rise of American English as the medium for exhange of scientific and technical information worldwide is a linguistic phenomenon. For some time, applied linguists in Britain have provided texts to meet the demand for English for special purposes and English for science and technology. Their works use a British form of language and cover British applications. Lately, American educators also have entered these fields. Typically, they cover the terms and concepts of a particular profession or trade like engineering or the use of hand tools, and they show model forms of technical communication, including resumes, letters, and reports. Technical English, American style, however, is not essentially professional jargon or simply standard English applied to special purposes. It is a distinct variety of American English with definable semantic features, morphology, and syntax. Its lexicon is delimited, and its phonology is characterized by low-level American phonetic rules. Along with the English writing system, it relies heavily on pictorial representation; and its rhetoric, strongly deductive, has distinguishable characteristics. Precise descriptions, like those provided here, may be useful as an aid in developing and implementing instructional materials in technical English. (Author/AMH)