the authz table only allows 255 characters // for identifiers, including JSON wrapping, which takes up 25 characters. For // now, we only allow identifiers up to 230 characters in length. When we are // able to do a migration to update this table, we can allow DNS names up to // 253 characters in length. maxLabelLength = 63 maxDNSIdentifierLength = 230 `identifier` varchar(255) NOT NULL, {"type":"dns","value":"example.com"} https://community.letsencrypt.org/t/i-want-use-max-255-octet-domain/51279