A general theory of ordering lexicographic entries in various languages is formulated. Basic concepts and principles of one-, and many-step ordering are discussed. The algorithms for one-step (alphabetic), two-step (alphabetic with diacritical marks) and many-step ordering (with attributes) are derived and illustrated on examples. A simple method of computer implementation is proposed. The method consists in creation and sorting of extended alphanumeric strings containing the information about all steps of ordering. The problems encountered in implementation of the theory: transcription of lexicographic entries into a standard ASCII format, identification of alphabetic units, diacritical marks, ligatures and contractions, as well as creation of extended strings, are discussed. A master program applicable to various languages is described and example application to Spanish language discussed.