Which block on SF-153 is designated for incoming Transaction Number?

Study for the Communication Security (COMSEC) Test. Use flashcards and multiple-choice questions with hints and explanations. Prepare effectively for your exam!

The correct choice for the block designated for the incoming Transaction Number on the SF-153 form is Block 6. In this context, Block 6 is specifically reserved for recording the incoming transaction number, which is essential for tracking the transfer of COMSEC material and ensuring accountability. Proper documentation of the transaction number helps maintain accurate records and facilitates communication between entities involved in the transfer. Understanding the specific functions of the blocks on forms like the SF-153 is crucial for compliance with operational security and effective record-keeping in communication security practices.