The paper addresses the problem of representation of grammatical information in dictionaries and reference-books by considering one particular title focused on the oikonymic system of the Volgograd region. A new concept of grammatical description is introduced, which is the degree of uniqueness of a geographical name within the region. Developing the rating scale for this parameter required consideration of such linguistic criteria as the word-formation pattern, the identity of the root morpheme or the entire lexical unit, the morphemic affi nity of the names with the same root. The new parameter proves particularly relevant in the view of occasional changes in the administrative-territorial division of the region, especially when deciding whether it is necessary/unnecessary to rename a particular locality. The study also takes to specify the grammatical norm regulating the choice of the case form of the toponym at its use with the generic term. Given the signifi cant number of differential features that are complementary, rather than hierarchical, it is proposed that each dictionary article has to include specific recommendations on the choice of the form of the proper name. Different patterns in the names of residents of particular settlements (katoikonyms) are described, related to the frequency of their use in regional, city and district newspapers. The authors also reveal the factors these variants of katoikonyms may be caused by, some pertinent to a certain historical period or else resulting from the peculiarities of the local toponymic system. The paper presents the structure of an article adopted for the forthcoming reference book the authors are working on, along with the samples of dictionary articles.