Subject

 – Is recommended for use when the range of topics is broad such as correspondence, reports, clippings, catalogs, research data, projects, plans and inventory lists.  The subject arrangement becomes a logical way to sequence information.

Alphabetical 

– Is recommended for use when records are retrieved by personal, organization, or agency names such as names, geographic locations, vendors, publications, or things usually filed in alphabetical order.

Numeric

 – Is recommended for use when the volume of records is large and have unique numbers that naturally sequence the order.  i.e., using numbers in various combinations, such as date, control-section, and job, etc.

Alpha-Numeric

 – Consists of a combination of letters and numbers. i.e., the alpha designation is SAF for the Safety, followed by a primary subject heading in a structured-functional system.  SAF-001 Safety Manual (General).  Alpha-Numeric can be a decimal numeric (SAF-001), duplex-numeric (SAF-001-GEN), or block-numeric (SAF [100-499]), and Title/Numerical sequence.