In ancient China, personal residences and government offices used to hang plaques above their doors, and their handwriting and calligraphy were neat, vigorous and elegant. In foreign countries (western countries), many doorplates and plaques are hung on the doors, and many of them are carved with stones on the side of the doors.
At present, many institutions in our country are used to writing or lettering with wooden signs as doorplates, which first appeared in various institutions produced by the Revolution of 1911, but mainly originated in the Central Soviet Area in the 1920s and 1930s, probably imitating the practice of the Soviet Union, and should be regarded as the product of the combination of soil and foreign countries. Wood flat, painted with white paint, books (or engravings) in black, concise and eye-catching, economical and practical.
Nowadays, with the improvement of production and living conditions, government agencies and other units have changed the material of doorplates to steel, copper and other metals, and the format of doorplates has also changed to long, square, round, hanging on doors, doors and other styles. This reflects the development of society. Of course, no matter how it changes, the solemnity of the government agency number cannot be changed.