--server-option=<option>::
Transmit the given string to the server when communicating using
protocol version 2. The given string must not contain a NUL or LF
- character.
+ character. The server's handling of server options, including
+ unknown ones, is server-specific.
When multiple `--server-option=<option>` are given, they are all
sent to the other side in the order listed on the command line.