1. A method of filtering a plurality of data items according to user input, wherein each of the data items is identified by a multiple-character identifier, the method comprising: presenting a collection of individual characters to a user via a computer device, wherein any of the individual characters may be selected by the user; receiving to the computer device a character sequence from the user having Y characters, wherein the character sequence comprises at least one character selection selected from the collection of individual characters, and wherein Y is a number less than the multiple-character identifier for at least one data item; for each character selection of the character sequence, associating at the computer device more than one character from the collection of individual characters with the character selection; filtering the plurality of data items via the computer device based on the associated characters corresponding to each character selection, wherein the filtering comprises a comparison of the associated characters of the character sequence to every Y subset of characters within the multiple-character identifiers of the data items; and presenting a list of filtered data items to the user, wherein at least one data item of the list includes associated characters of an entirety of the character sequence received from the user as an internal character string of the at least one data item, and wherein the internal character string does not include a first character of the multiple-character identifier of the at least one data item.