once and the data on them read with little handling.

The latest edition of the Department of the Navy Information and Personnel Security Program Regulation, OPNAVINST 5510.1, defines the element of security for the various stowage containers used for classified material. In determining the security of file cabinets, there are three factors to be considered: (1) portability, (2) ease or difficulty of opening by unauthorized persons, and (3) fire resistance.

A portable cabinet has no security value because it can be carried away by a thief and opened at leisure by whatever methods are necessary. Combination locks are, in general, more secure than key locks. Some key locks are harder to pick than others, and the same is true of combination locks.

Wooden cabinets have little security value. They offer poor protection against either unauthorized entry or fire. Metal cabinets offer more protection than wood, but vary in degree of security according to the thickness of the metal and the sturdiness of their construction. In a serious fire, the contents of all but the heaviest cabinets may be charred. Vaults are the most secure, but they also vary in degree of protection against both entry and fire.

The foregoing are principles to be considered in connection with the use of files for classified matter. For more details, or to determine whether security is adequate in any specific case, you should refer to the OPNAVINST 5510.1.

Filing Supplies

Folders are used to keep correspondence orderly in the files. Standard file folders are available in two sizes: letter size, 9 x 11 3/4 inches; and legal size, 9 x 14 3/4 inches. Folders are packed in boxes of 50 and ordered according to tab positions desired. Tab positions are available in either one-third cut (three positions to each set) or one-fifth cut (five position; per set).

For general correspondence, you should arrange the folders using tabs in the first, second, and third positions consecutively throughout the file drawer. The total number of folders and the appropriate primary, secondary, or tertiary subject identification numbers (or the symbols) to be used for each folder should be determined by the volume of subject matter to be filed in connection with the amount of filing drawers available. At this point, you should refer to the Navy standard subject identification codes for help in estimating immediate and future needs.

You may handprint the subject identification number on each folder using large lettering, with printer's ink, for clarity and depth of color to aid in visual sighting. An example of such a folder arrangement in a file drawer is illustrated in figure 2-13.

STANDARD SUBJECT IDENTIFICATION CODES (ASIC)

The standard subject identification code (SSIC) is a number that stands for the subject of a document. SSICs are required on all Navy and Marine Corps letters, messages, directives, forms, and reports. The use of SSICs provides a method for filing documents with consistency and retrieving them quickly. The latest edition of the Department of the Navy File Maintenance Procedures and Standard Subject Identification Codes, SECNAVINST 5210.11, provides the list of SSICs.

There are 13 subject groups under the Navy's SSIC system, each group being identified by a four- or five-digit numeric code. They are as follows:

1000 Series - Military Personnel

2000 Series - Telecommunications

3000 Series - Operations and Readiness

4000 Series - Logistics

5000 Series - General Administration and Management

6000 Series - Medicine and Dentistry

7000 Series - Financial Management

8000 Series - Ordnance Material

9000 Series - Ships Design and Material

10000 Series - General Material

11000 Series — Facilities and Activities Ashore

12000 Series — Civilian Personnel

13000 Series — Aeronautical and Astronautical Material