This service provides an onion site accessible over Tor
Description
Tor is a software for anonymous communication that directs Internet traffic through an overlay network. Onion sites are only available through Tor browser and provide additional security and anonymity to users.
Indeed, it’s quite rare, but I’d say people generally don’t use Tor to access the Internet, so it won’t affect them much if the service has an onion site or not. How about a weight of 40?