1. In giving the password, if your force includes men of different cities or nationalities, take care not to give a word whose meaning can be equally well expressed by another word, as for instance Dioscuri and Tyndaridae, where the two different words mean the same; 2. or again Ares and Enyalius, Athena and Pallas, sword [xiphos] and cutlass [encheiridion], lamp and light, and similar expressions which are hard to remember because of the different usages in every nation [ethnos], and are a source of danger if a dialect form instead of one generally familiar is issued as the password. 3. Thus when mixed mercenary troops or allies of different nationalities form part of your force, such passwords should be avoided.
The passwords given should therefore be easy to remember, and as nearly related as possible to the business in hand: 15. for instance, for a foray ‘Artemis the Huntress’; for secret exploits ‘Hermes the cunning’; in case of an assault ‘Heracles’; for open attacks ‘Sun’ and ‘Moon’; and so on as far as possible, using words that will be intelligible to all. 16. Iphicrates used even to say that rounds and sentries should not have the same password, but that a different one should be assigned to each: for instance, the man challenged would answer ‘Zeus the Saviour’ (if this happened to be the word), and the reply of the challenger might be ‘Poseidon’. This would minimise the risk of disasters arising from the betrayal of a password to the enemy.
17. In case the guards get separated, arrange in advance for them to communicate by whistling: for this will convey nothing to those who do not know it, whether they are Hellenes or Barbarians. 18. But look after your dogs: otherwise, when they hear the whistle, they may cause trouble. Whistling was used to collect the troops at Thebes during the recapture of the Cadmeia, when they got separated and did not know one another in the dark.
19. Rounds and patrols should both demand the password: it is no use for only one to do so. For an enemy might challenge just as well as a man going the rounds.
25. Signs to accompany the password
1. A sign is sometimes employed as well as the password to prevent panics and for the better recognition of friends. 2. These signs must be as distinctive as possible, and such as an enemy will be least likely to recognize: here are some examples. On dark nights the challenger should also utter some further sound or simply make an audible signal, and the man challenged should give the password and also utter a prearranged sound or make some noise. But in god light the challenger should take off his cap [pilos], or, if he has it in his hand, put it on; 3. or he may press his cap down over his brow, or set it back on his head, 4. or plant his spear in the ground as he approaches, or pass it over to his left hand, or hold it aloft in his hand, or simply raise it; the other man should give the password in answer and also make some such prearranged movement.