What does the right army habit mean?

Pinyin:

yòu jūn xí qì

Explanation:

Right Army: Wang Xizhi, a famous calligrapher in Jin Dynasty, was once a general of the right army and was called Wang Youjun. Metaphor blindly imitates the ancients and cannot create its own style.

Source:

Cao Cao wrote in calligraphy: "Taking off your wrist can still exist in your heart, and there is no habit of being a regular army."

Example: