A clever soldier, especially a unit below the company that is responsible for marching alert. According to the size of the army, it is called advanced class, advanced platoon and advanced company. There are tasks such as combat search, reconnaissance of the enemy and observation of the terrain.
Head is a word in ancient Chinese, which has multiple meanings, but the main explanation is leader, but there are other explanations in the texts of special periods. Refers to a small unit that acts as a guard in front of the troops when marching.