When a non-service COMSEC account is involved, what document must be mailed signed?

• A. Form SF-153
• B. Document SF-234
• C. Form 345-A
• D. Account Transfer Form

Answer: (A)

In the context of Communication Security (COMSEC), when dealing with non-service COMSEC accounts, the proper document that must be mailed in a signed format is Form SF-153. This form is used for the receipt and transfer of COMSEC material and accounts, ensuring proper authorization and accountability. The significance of the SF-153 lies in its role in maintaining the integrity of COMSEC operations. By requiring a signed version of this form, it ensures that the transfer or acknowledgment of sensitive material and accounts is conducted in a secure and traceable manner, which is critical for operational security.

The other forms or documents listed do not fulfill the same role as SF-153 in this context, as they pertain to different processes or types of account management that do not specifically relate to the receipt and transfer of COMSEC materials. Therefore, the use of Form SF-153 is essential in situations involving non-service COMSEC accounts.