1. A method comprising: modifying a query string of characters using a set of heuristics; performing a character-by-character comparison of the modified query string with at least one known string of characters in a corpus in order to locate an exact match for the modified query string; and responsive to not finding an exact match, performing the following steps in order to locate an equivalent for the modified query string: forming a plurality of sub-strings of characters from the query string, the sub-strings having varying lengths such that at least two of the formed sub-strings differ in length; and using an information retrieval technique on the sub-strings formed from the query string to identify a known string of characters equivalent to the query string.