The research aims to identify the features of the military sublanguage in the system of the English language from the perspective of the functional theory of lexicography and determine the role of a user learning military English and a non-lexicographic situation created by him when compiling dictionaries. The paper reveals the tasks of theoretical lexicography under a non-lexicographic situation (the study of military English and military translation) and dwells on the needs of a specialized dictionary user that arise in such a situation. The scientific novelty of the research lies in the fact that it is the first to determine the influence of a specific user type and a non-lexicographic situation he creates (the study of military English and military translation) on the process of compiling a military translation dictionary, including e-dictionaries. As a result, it was substantiated that the functional theory of lexicography should be developed through the analysis of corpora-related situations (including non-lexicographic situations linked to teaching a foreign language for specific purposes). The author proves the need to create e-dictionaries for military translation, whose corpora will be based on the texts that take into account students’ communication-oriented and cognitive-oriented needs.