The article deals with the spelling of individual names (names of literary, folklore, film or cartoon characters) that include appellative words. This is a special case of transitive phenomena in onomastics. Appellative names transform into proper names, as well as (when using these names figuratively, in the characterizing function) vice versa. Transients are a spelling-unstable group of nominations whose spelling cannot be considered conventional at the moment.
The studied language material shows that the spelling of a multicomponent name depends on its structure and the nature of its components. There are several structural types of individual names: a) a phrase that includes a proper name with an appellative (generic concept) in the preposition (such as baron Myunhauzen, tsar' Saltan, doktor Ajbolit), b) an adjectival or descriptive indivisible construction initially consisting only of appellatives (such as Sinyaya ptitsa, Malen'kij prints, Snezhnaya koroleva, Kot v sapogah), c) a hyphenated construction (Ivan-tsarevich, Konek-gorbunok, Karabas-Barabas), etc. Nominations that do not belong to standard structures are more likely to experience spelling fluctuations.
The current spelling rules for capitalization are based on a thematic principle (proper names of people, geographical names, names of governmental bodies, etc.). With this approach, the language features of the nominations remain undetected, and spelling patterns are not established. Replacing the thematic approach with a structural-language approach seems to be productive for further study of spelling in the field of letter case.