8.18
5.6 
Originates from Keywords.
5.6.1 Naming Rules
5.6.2 ?,化句、句化、化
Resembles , because they are similar in data struct sence.
5.6.3 ming/racket/base
| (require ming/racket/base) | package: ming | 
5.6.4 ming/racket/keyword
| (require ming/racket/keyword) | package: ming |