Troops under orders to proceed overseas must be made to understand why secrecy is essential, and that everyone of them possesses information which, in the hands of the enemy, might cost their own lives, the lives of thousands of their comrades, and the success of a major military operation.

Vital matters which must be kept secret from everyone whose official duty does not require the information are:

a. Port of embarkation.

b. Name of ship, or of other ships in the convoy.

c. Date or time of sailing.

d. Destination or route of convoy.

e. Any particulars concerning His Majesty's Forces or the types and quantities of matériel embarked.

It is equally important not to talk to anyone about these subjects if your information is based only on guesswork. The guess may be right.

The fact that a unit is shortly to proceed overseas must necessarily be known to certain people during the preparatory period. Nevertheless, the fewer people who know, the better. And the less they know, the less the enemy is likely to find out.

Perhaps you suppose that the little you have to tell cannot be important. If you believe this, you are wrong. As a rule, the enemy discovers vital information only by piecing together several small items of intelligence, like a jigsaw puzzle. It may be that your little fact gives sorely needed verification. It may well be that the movement of your unit is part of a large-scale operational movement, which could fail entirely as a result of your breach of security.

Although everyone knows that classified information about the movements of troops and convoys must not be discussed in a public place (or even over the telephone), not everyone realizes that it is just as dangerous to pass this information along to relatives and lifelong friends. No doubt you are sure that they will not tell anyone, since you asked them not to. But YOU were instructed not to tell anyone, and you have already done so. They may follow your example. After all, they are not in as immediate physical danger as you are.

"Bowels open, mouth shut" is a very good motto to observe, not only in the Army, but throughout life.