whois 2a0e:aa06:400::/44
2020/02/19，突发奇想在反向查询区域添加了 A/AAAA/CNAME 等记录，好像能当作普通的域名用（但是各大证书厂商不承认的样子orz）。
2020/02/19, I hit upon an idea that if adding A/AAAA/CNAME record to Reverse Lookup Zone works. It really can be used as normal domains, but it seems certificate authority won't issue a certificate for it.