4. The computer implemented method of claim 3 wherein the encoding bitmap is located in the memory device.
3. The computer implemented method of claim 2 further comprising: not identifying a match within the memory device to another converted filename of another retrieval request; retrieving a list of previously-used text encodings from the encoding bitmap; using a text encoding from the list to convert the filename of the other retrieval request to Unicode text encoding to form a new converted filename of the other retrieval request; and attempting to identify a match within the memory device to the new converted filename of the other retrieval request.