Query: What army was considered to be the volunteer army?
Context: The Eastern Han court favored the recruitment of a volunteer army. The volunteer army comprised the Southern Army (Nanjun 南軍), while the standing army stationed in and near the capital was the Northern Army (Beijun 北軍). Led by Colonels (Xiaowei 校尉), the Northern Army consisted of five regiments, each composed of several thousand soldiers.