b. Type T o: at the margin on the first line under the from block. Four spaces follow the colon.
c. Whenever practical, include a code or persons title in parentheses right after the activitys name. Add the word Code before codes that start with numbers. A code that starts with a letter is readily identifiable as a code without the added word.
11. Via Block
a. List commanding officers in the via block as if composing a from or to block. Give a complete mailing address, ZIP Code included, if you want it for a record.
b. Type Via: at the left margin on the first line below the to block. Three spaces follow the colon.
c. Number via addressees if you list two or more. Routing starts with the addressee listed first. When going down a chain of command, first list the next lower echelon. When going up your chain of command, first list the next higher echelon.
d. Follow your chain of command when corresponding on substantive matters such as command decisions, policy issues, and official recommendations. Such routing keeps intermediate commands informed and allows them to comment or approve. For variations see SECNAVINST 5216.5C.
12. Subject
a. Craft the subject to make it genuinely informative.
b. Type Subj: at the left margin on the second line under the last line of the previous heading. Two spaces follow the colon. Use normal word order. Capitalize every letter after the colon. When a subject appears elsewhere in a letter, capitalize the first, last, and other key words as if you were writing a book title.
13. References
a. Use only those references that bear directly on the subject at hand. Avoid unnecessary or complicated references. Many letters need no references at all, while others are complete with a reference to only the latest communication.
b. Be sure to mention in the text any reference cited in the reference block. List references in the reference block by following the order of their appearance in the text.
c. Avoid most NOTAL references. A NOTALnot to allreference is a document that some addressees or all of them neither hold nor need. Work to cite directives, correspondence, and messages held by all addressees. For alternatives to NOTAL references, see SECNAVINST 5216,5C.
d. Type Ref: at the left margin on the second line below the subject. Use a lower-case letter in parentheses before the description of every reference, even a single one. Three spaces follow the colon. One space follows the closing parenthesis. When referencing correspondence, include: (1) SNDL short title of originator, (2) type of correspondence (ltr, spltr, or memo), (3) SSIC, (4) originators code by itself or in a serial number, and (5) date. SECNAVINST 5216.5C also shows how to reference messages, endorsements, telephone conversations, instructions, notices, forms, reports, and publications.
14. Enclosures
a. Try to keep letters short, down to one page whenever possible, and use enclosures for lengthy explanations that cannot be avoided. List enclosures in the order of their appearance in the text. In the text spell out the word enclosure. Describe an enclosure like a reference.
b. Type Encl: at the left margin on the second line below the last line of the previous heading. Use a number in parentheses before the description of every enclosure, even a single one. Two spaces follow the colon. One space follows the closing parenthesis.
c. Normally, send one copy of the basic letter plus any enclosures to all addressees. Avoid sending an enclosure if an addressee has it already or if bulk or other factors make furnishing it impractical.
d. When sending more than one copy of an enclosure to all addressees, note the quantity in parentheses after the enclosures description. For variations in the distribution of enclosures to copy-to and via addressees, see SECNAVINST 5216.5C.
e. Mark an enclosure on the first page only, in the lower right corner, whether the text is arranged normally or lengthwise. Type, stamp, or write Encl plus its number in parentheses. Pencil may be used so an addressee can remove the marking easily should the enclosure be needed