社会统一信用码校验和信息含义 ref: https://wenku.baidu.com/view/19873704cc1755270722087c.html http://blog.sina.com.cn/s/blog_76e84df30101eb63.html http://blog.csdn.net/archer119/article/details/52904286 http://www.showcj.com/show-2-60.html 18: http://qyj.saic.gov.cn/zyfb/gszjfb/201612/t20161208_232473.html