Chen, private house, deep house; The location of the North Star (Beichen) and the hub of the stars and the sky. Later, it refers to the residence of the emperor, and it is also extended to the title of the throne and the emperor; It also refers to the Heavenly Palace, where the Emperor of Heaven lived.
Kay, literally: there are certain norms or standards. For example, an example means that a person's behavior and way of doing things can provide reference for others. Block letters, a kind of calligraphy fonts, have certain standards.