In recent years, there has been a sharp increase in targeted computer attacks on the information resources of the Russian Federation and enterprises and individual organizations. In these conditions, the problem of protecting information processed in digital form in government information systems and personal data information systems is significantly updated. This problem accumulates the experience of mastering information technologies in developed countries, is interdisciplinary in nature and is therefore studied by technical, legal and other sciences. Based on open publications, the author summarizes information about the approach of the United States and other Western countries to the protection of unclassified controlled information. Using the analysis of official documents on information security, the article highlights a complex structured approach to the differentiation of protected unclassified information, its special labeling, which allows for «end-to-end» control over the circulation of information during its entire life cycle of existence. Studying the US experience in the field of information security in information systems allows us to deepen our understanding of the content and forms of confidential information, clarify the directions of development and adjust the methods of protecting official information of limited distribution.