What does ssh -w

I was reading the manual of ssh, I'm used to do tunneling with -L -R and -D, and I was surprised to see another option : -w

-w local_tun[:remote_tun]
             Requests tunnel device forwarding with the specified tun(4) devices between the client (local_tun) and the server (remote_tun).

             The devices may be specified by numerical ID or the keyword “any”, which uses the next available tunnel device.  If remote_tun is not specified, it defaults to “any”.
             See also the Tunnel and TunnelDevice directives in ssh_config(5).

             If the Tunnel directive is unset, it will be set to the default tunnel mode, which is “point-to-point”.  If a different Tunnel forwarding mode it desired, then it should
             be specified before -w.

I don't understand what's the use case of this option ? None of the website that explain ssh tunneling talk about it.

I'm curious !