The so-called "pan-domain name resolution" refers to: using the wildcard * (asterisk) as a secondary domain name to achieve that all secondary domain names point to the same IP address.
For example, your domain name is abc.cn:
Make a sub-domain A record of *.abc.cn pointing to 188.8.131.52, then when the entry is effective, the visitor enters "123.abc.cn"
Or "123.123.abc.cn" can even be "3d293k.6543.ww.a.abc.cn" and any character can point to the IP address 184.108.40.206.
But please note:
"-" middle crossbar
"/" left diagonal
These three characters cannot be applied in pan-parsing. The problem occurs when the three characters cannot exist in the first character of the secondary domain name.
-.abc.cn or -5.abc.cn
..abc.cn or .5.abc.cn or .abc.cn
This is not resolved.