The encyclopedia, or classified, system is ideal for large volumes of records arranged by subject. Subjects are grouped under broad categories. These are then broken down alphabetically into more precise subjects. Major subject headings appear on dividers and secondary headings as well as major headings appear on individual folders. Geographic systems use location to arrange records.
Major headings can be countries, states, counties, cities or any other geographic location.
Secondary headings are arranged alphabetically under these major headings. Numeric classifications use numbers or dates to arrange information. Straight numeric systems simply number files consecutively and arrange them in sequence. Straight numeric systems are simple to use, simple to manage, and simple to expand. There are problems with straight numeric systems, however.