This reference guide provides information on using different types of caches. The book discusses possible options for hiding places, methods for creating them and the necessary tools, describes the devices and materials for their construction. Recommendations are given for arranging hiding places at home, in cars, on a personal plot, etc. Particular attention is paid to methods and methods of monitoring and protecting information. A description of the special industrial equipment used in this case is given, as well as devices available for repetition by trained radio amateurs. The book provides a detailed description of the operation and recommendations for the installation and configuration of more than 50 devices and devices necessary in the manufacture of caches, as well as those intended for their detection and ensuring safety. The book is intended for a wide range of readers, for everyone who wishes to become familiar with this specific area of the creation of human hands.