The object of the considerations is the spelling of a subgroup of appellativized or being under the process of appellativization proper names such as: Don Kichot, Zosia Samosia, nowy wspaniały świat, Wielki Brat, siedmiu wspaniałych. Such language units` orthography is clearly unstable, because of some reasons: firstly the doubts about their status (the users' uncertainty whether they are proper or common names), secondly the etymological relations with proper names which are still noticeable even after the change of such units` status (the acquaintance of etymology), and thirdly the writers` habits. As the analysis shows the instability of using capital letters may be the signal of displacement within the lexical subsystem, creation of new units of nomen appellativum character.