Firewall alias FQDN field rejects IDNs (Internationalized domain names)
When creating a firewall alias and entering "www.bücher.ch" as the FQDN, pfsense gives an error stating:
"www.bücher.ch is not a valid host address, FQDN or alias."
This message is incorrect. www.bücher.ch is a valid FQDN.
Happily, entering the punycode representation (www.xn--bcher-kva.ch) results in everything working fine (alias can be created, rules using the alias work, ex: I can block that site).
I suggest that pfsense should accept Unicode characters in the FQDN textfield and internally convert them to punycode to pass down to pf or whatever other lower layers need it.