"Ya" is the ancestor of dictionaries. A rich collection of ancient Chinese vocabulary. It is not only the dictionary of the ancestors, or ancient Chinese classics - classics, a kind of "Thirteen Classics" is the core part of traditional Chinese culture. "Ya" is the first dictionary, "Seoul" is "near" means (and later writing "near"), "Ya" is a "positive" means, here refers specifically to "elegant language", that voice, vocabulary and grammar are normative standard language. "Ya" means close, in line with Yayan, that Yazheng words to explain the ancient words, dialect words, make it nearly specification.