Abstract: A filing system is provided for locating a particular file contained in a file holder which contains a plurality of files. The apparatus includes a machine-readable code mounted on each of the files, a guide attached to each file holder, a scanner for reading the codes on the files in a file holder, and an indicator for indicating when the particular machine-readable code corresponding to the particular file is located. The apparatus uses an improved bar code in which character boundaries are eliminated and the number of ONE's and ZERO's in a code are variable, resulting in increased data density. The unique numeric values which result from the improved bar code sparsely populate the possible range of values, and therefore a mapping algorithm is provided to map the bar code values to a sequential numeric system for ease of use.