The customer might not even see it without compatible software, or if using a different port number or protocol, or if not using DNS to access something, or usi

The customer might not even see it without compatible software, or if using a different port number or protocol, or if not using DNS to access something, or using a different DNS. Or if you are using a web browser but with customized settings that make it incompatible. Same with many hotels. If you are not even using HTTP(S), or DNS, then it won't work, and even if you are using HTTP but not with a web browser program, it won't work (there is a HTTP response code (511) defined for this purpose at least), using nonstandard port numbers, etc. For terms of service requirements, one possibility to avoid these problem is to make the printed terms of service document with the wi-fi password mentioned in that document.