n. ~ A technique to classify materials using numbers to represent concepts and any subdivisions.
In a decimal filing system, related concepts are often grouped in units of ten, and subdivided as necessary for greater specificity. Major categories are typically integer values; secondary and tertiary headings are separated using subsequent decimal points. For example, 50 through 59 might be used for major classes of policies. Policies for fringe benefits might be coded 55, and the maternity leave policy might be coded 55.2.