The tilde backtick symbol (`) seems allowed in the host. In the spec it is not allowed:
host = IP-literal / IPv4address / reg-name
reg-name = *( unreserved / pct-encoded / sub-delims )
unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
sub-delims = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="
require "addressable"
Addressable::URI.parse("htttp://`www.example.com")
#=> #<Addressable::URI:0x3c URI:htttp://`www.example.com>
The
tildebacktick symbol (`) seems allowed in the host. In the spec it is not allowed: