Zhengzitong states that this is a vulgar form of the character dian. In the Admonition of the Bing Province Governor by Yang Xiong (Yang Xiong Binzhou Mu Zhen), it is written: The highest grade is to manifest morality, the next is to display military force; if both morality and military force are overthrown, there is nothing that will not fall into decay and ruin. The character dian is derived from the two components of the character zhen.