17. 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 at the computer device a character sequence from the user having a first number of characters having at least two characters in a first character order; 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 including the received characters; 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 in the first character order to every subset of characters equal to the first number of characters within the multiple-character identifier of each item of the plurality of 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.
17. 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 at the computer device a character sequence from the user having a first number of characters having at least two characters in a first character order; 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 including the received characters; 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 in the first character order to every subset of characters equal to the first number of characters within the multiple-character identifier of each item of the plurality of 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. 19. The method of claim 17 , wherein the multiple-character identifier of the at least one data item comprises a second number of characters greater than the first number of characters of the received character sequence, wherein the multiple-character identifier comprises a first character and a last character in order of the second number of characters, and wherein the internal character string includes the last character of the second number of characters.