Engineers have forgotten how to write instructions. This conclusion was made by the author based on the study of technical documentation as part of the work on import substitution of foreign software and information systems developed on their basis. The author, an engineer with 15 years of experience in the field of information technology, makes an attempt to improve the current situation. The book presents both the methodological component of writing clear instructions and recommendations for its design. The book is addressed to engineers, as well as engineering students, and can be used as a reminder when writing instructions.