进一退三注码法简介：The reason why it is called Xuanwumen is because Xuanwu, one of the four ancient gods, represents the north. In the Qing Dynasty, it was renamed Shenwumen to avoid the name taboo of Emperor Kangxi Xuan Ye.
The reason why it is called Xuanwumen is because Xuanwu, one of the four ancient gods, represents the north. In the Qing Dynasty, it was renamed Shenwumen to avoid the name taboo of Emperor Kangxi Xuan Ye.
