What are the general rules of official seal?

If there is no word in the lower arc of the seal, the lower sleeve type is adopted, that is, the lower edge of the seal covers the moon by the year; If there are words under the seal, the middle sleeve type is adopted, that is, the center line of the seal is pressed on the writing date.

The seal should be clear and standardized, requiring "words can not be pressed, and dates can not be pressed". That is, riding the year over the moon, also known as "riding the year over the moon."