The present study is devoted to the description of the methodology for predicting word combinations equivalent to compound abbreviated appellatives, which is based on the use of the correlation of semantic cases of equivalent word combinations and structural schemes of a relational deciphering stimulus. The relevance of the work is determined by the fact that it is a description of the applied part of the methodology for compiling the “Explanatory Dictionary of Compound Words”, and also by the fact that, on a synchronous cut of the language, the relational deciphering stimulus is a productive unit of the equivalence nest, which, realizing the actant-numerical semantics of the presentative and modifier, reflects various semantic roles of the abbroconstruct of a compound word. The object is a relational deciphering stimulus, i.e. such a regular model for deciphering an abbreviation that implements the actant and actant-numeric characteristics of the presentative and modifier. The purpose of the article is to describe the methodology for filling gaps in the equivalence nest of a compound abbreviated appellative. The paper uses linguistic methods and techniques for analyzing units equivalent to a compound word, in particular onomasiological - to clarify semantic roles in the formation of nests of equivalence and abbreviation pairs, a descriptive method to derive a general idea of relational semantics in the nest of equivalence of compound words, the formalization method was used in building models formal structure; component analysis was used to study the structure of specific equivalence nests; with the help of quantitative analysis, the language material was selected. The use of basic methods of analysis and synthesis made it possible to determine the patterns of not only the formation of tokens, but also lemmas that activate the semantics of the abbroconstruct, to substantiate the semantic dependence of the onomasiological feature on the onomasiological basis when predicting compound abbreviated appellatives, to establish the parameters for filling in the table of relational decoding stimuli and the prediction matrix. The obtained theoretical conclusions can be used in the collection and processing of lexicographic material, compilation of dictionaries, as well as in the study of word-formation processes of the modern Russian language and the description of specific abbreviation groups.