Abbreviations are used in the following items of the heading: Subject (Subj:); Reference (Ref:); and Enclosure (Encl:). When referred to in the text, these are spelled out, and the initial letter in these cases is not capitalized unless it is the first word of a sentence. A heading entry that is too long to be completed on one line is run over to the next line, flush with the first word following the colon.

SENDER'S SYMBOLS. - Three types of symbols are to be used on correspondence for reference and record purposes. They are the (1) standard subject identification code (SSIC), (2) originators code by itself or in a serial number, and (3) the date. These symbols are typed in the upper right corner, blocked one below the other.

When a "Refer to" line is printed on the stationary, it governs the location of the identification symbols. The standard subject identification code (SSIC) is a numeric code used for grouping all correspondence and directives. SSICs are discussed later in this chapter. The latest edition of SECNAVINST 5210.11 contains the SSICs. If the drafter of the letter has omitted this information from the rough draft of the letter, you will have to look up the SSIC in the SECNAVINST 5210.11. The originators code may be the office symbol of the drafter, the hull number of the ship, or other unique code dictated by local policy. The originators code MUST be used; however, it may or may not be used with a serial number. All classified correspondence is serialized. Unclassified correspondence may or may not be serialized,

Figure 2-9. - Standard letter.