This standard applies to newly developed and modernized electro-vacuum devices used in radio-electronic equipment, and establishes a system of symbols. This standard does not apply to gas-discharge and gas-filled sources of high-intensity optical radiation and microwave devices, as well as to transmitting tubes, photocells, photomultipliers, electron-optical converters (except for X-ray electron-optical converters). This standard is intended for use by enterprises, organizations and other subjects of scientific and industrial activity, regardless of forms of ownership and subordination, as well as by federal executive authorities of the Russian Federation involved in the development, production, operation of electrovacuum devices in accordance with current legislation