The manual is the first attempt in domestic linguistics to generalize all ideas about euphemisms into a coherent theory of euphemia, which is based on both linguistic and extralinguistic criteria. For the first time in Russian studies, clear linguistic criteria have been introduced into the theory of euphemisms, allowing them to be distinguished from a large number of linguistic units associated with a figurative name. The work considers general issues of the theory of euphemisms, the conditions for the functioning of substitute names, characterizes the main types of euphemisms of the Russian language, provides various classifications, describes their system connections and relationships.