(For consolidation, see note to Scheme 7.)
18. Your duty towards the enemy is your duty towards your neighbour reversed. Think how he could make himself most objectionable to you and act in this manner towards him.
19. Always be certain that you understand your orders, and if you are in doubt never hesitate to ask and make certain, even should your commanding officer have a short temper.
20. If you are detached for any specific purpose you should always rejoin your unit when you have accomplished what you were told to do.
21. Do not fail to give negative information. Young officers are very apt to neglect this. It may be of great importance to a commanding officer to know that a certain place is not held by the enemy, and this is just the kind of information that his patrol leaders are apt to forget to send him.
22. Always insist on any verbal order you may give being repeated to you by the recipient before he leaves your presence.
23. In a retirement you send men to the rear with orders to take up another position to protect your retirement; always see that they are accompanied by a competent leader, or when the last party falls back they will very likely find that their retirement is unsupported.
Try to remember these axioms. My subsequent letters will be founded on their application.
Your affectionate father,
“X. Y. Z.”