There is an idiom called Xiaodian.

There is no idiom with "dot", and the idiom ending with "dot" is as follows:

Hard code, immutable rules.

As the earliest ancient book in China, Three Graves and Five Codes has been handed down.

Cite classics as the basis of argument.

Unpublished canon refers to the emperor's records and the immutable and indelible imperial edict system.

See "Juck Zhang National Heritage" in Juck Zhang National Canon.

What is a classic is that I don't know what book it is from and whether it is based on it.