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 These major groups are subdivided into primary, secondary, and sometimes tertiary breakdowns. The last three digits (the hundred group) of the code number designate primary subjects, the last two digits secondary subjects, and the final digit tertiary subjects. For example, the 5000 series, General Administration and Management, could be further broken down as follows: 5000 General Administration and Management 5 200 Management Programs and Techniques 52 10 Office Methods and Paperwork Management 521 1 Files and Records Systems Some of the smaller subject groups are not subdivided below the primary breakdown. Other larger subject groups are divided into many secondary and tertiary subjects, the extent depending upon the scope and complexity of the major subject. SSICs are used to number and identify directives. For example, the first SECNAV-issued instruction on the files system is SECNAVINST 5211.1, and the subject is “Mail and File Practices.” Subsequent revisions to this instruction are numbered 5211.1A, 5211.1B, and so forth When additional instructions on the subject of the files system are written, they are numbered 5211.2, 5211.3, and so forth. MISCELLANEOUS FILING PROCEDURES Most of the correspondence that you are required to file should have as SSIC. Even with an SSIC, you may have some difficulty deciding exactly where some correspondence should be filed because in some cases in may be filed under one or more SSICs. This is where your experience is needed. All incoming correspondence should be screened and classified. Classifying Classifying, as the term is used here, is the process of determining the correct subject group or name title symbol under which correspondence should be filed and subordinate subjects, if any, that should be cross-referenced. Classifying is the most important filing operation because it determines where papers should be filed. The proper way to classify a document is to read it carefully while you consider the following factors: The most important, definite, or concrete subject that is mentioned in the document The purpose or general significance of the document The manner in which similar documents are requested The subject identification code under which previous documents of a similar nature are filed The SSIC that is placed on the letter by the originator may not be appropriate for every office; therefore, the text of the letters should be thoroughly screened and the letters filed correctly. Parts of a document (enclosures or attachments) should be filed with the basic document, if feasible. Cross-Reference Filing Although official letters usually are confined to one subject, they often may be properly classified under two or more file subjects; therefore, they may be filed under more than one file number. In such cases, a system of cross-referencing (indexing) is desirable. Cross-referencing serves a useful purpose in locating material but should not be overdone. Not every document needs to be cross-referenced. It is a waste of time to list every cross-reference you can possibly think of. Try to select only those that will likely be of use. An endorsement should not be cross-referenced unless it contains subjects that are not covered by the basic correspondence. Charging Out Materials The maintenance officer, division officers, or others in your activity use the correspondence maintained in your files. In many cases, they will only need to see the files on particular subjects and may not need to remove the files from the maintenance administration office. On other occasions, they may 2-21