He paper covers structural and informative features of the specific type of vocabulary denoted by a number of different terms in linguistics and translation studies. Among most widely used are such terms as culturonym, realia, nationally-determined lexical unit, etc. Researchers are usually based on either external features of such vocabulary (according to subject classification) or its functions (according to etymology and/or degree of acceptance in a lexicon). In translation, universal lexical units with standard lexical counterparts in another language may become a sudden challenge to require a special translator solution. Actually, any lexical unit without a sign of culturonym characteristics can appear in the «strange category». To explore this phenomenon, the informational-semiotic criterion may be useful.