In my opinion, in ancient training, the password was also called, regardless of infantry or cavalry, but it could not be 1-2- 1 as it is now. The purpose of shouting passwords is to keep soldiers in a good pace and boost morale with strict discipline. Uniformity, discipline and good training are very important for the army. Shouting passwords is a good training method, which was also the case in ancient times, so it was also called passwords in ancient times. The current password shouting did not suddenly appear, it must have evolved and developed, and the source must be ancient, so the ancient password shouting must be different from the current password shouting. Language is developing. Now 1-2- 1 comes from ancient times. I don't know how it was called in ancient times, but it is definitely different from 1-2- 1 now.