2 Help: Use PROTOCOL for any URL missing a scheme
6 Tells curl to use \fIprotocol\fP for any URL missing a scheme name.
10 curl --proto-default https ftp.mozilla.org
12 An unknown or unsupported protocol causes error
13 \fICURLE_UNSUPPORTED_PROTOCOL\fP (1).
15 This option does not change the default proxy protocol (http).
17 Without this option curl would make a guess based on the host, see --url for