1. A system comprising: a dictionary manager embodied via executable instructions stored on a computer-readable storage medium, the dictionary manager including: an item input engine configured to obtain a plurality of item character strings, each item character string representing an item in a catalog, each item associated with a category; a brand input engine configured to obtain a plurality of brand character strings associated with the category; a brand matching engine configured to determine, for each item character string included in the plurality of item character strings, whether a matched substring of the each item character string represents a match with one of the obtained brand character strings; a matching indicator engine configured to generate a matching indicator indicating that the each item character string includes a match with the one of the obtained brand character strings, based on a match result of the matching determination by the brand matching engine; a correlated segment engine configured to obtain, for each one of the obtained brand character strings, and for each one of the item character strings that includes a match with the each one of the obtained brand character strings, one or more correlated segments, other than the matched substring, of the each one of the item character strings that includes a match with the each one of the obtained brand character strings, based on determining that the obtained correlated segments are correlated, greater than a predetermined correlation threshold, with the each one of the obtained brand character strings; and a hierarchy generator configured to generate a dictionary hierarchy based on the obtained correlated segments.