One of the essential aspects is described of an expert system (called LEXICOGRAPHER), designed to supply the user with diverse information about Russian words, including bibliographic information concerning individual lexical entries. The lexical database of the system contains semantic information that cannot be elicited from the existing dictionaries. The priority is given to semantic features influencing lexical or grammatical co-occurrence restrictions. Possibilities are discussed of predicting selectional restrictions on the basis of semantic features of a word in the lexicon.