The Tor Project has been working with other members of the Peer to Peer community to register several Special-Use Domain Names. This standardization work is joint work between Facebook and the Tor Project amongst others in an effort to help secure users everywhere. With this registration, it is should also be possible to buy Extended Validation (EV) SSL/TLS certificates for.onion services thanks to a recent decision by the Certification Authority Browser Forum. We think that this is a small and important landmark in the movement to build privacy into the structure of the Internet.”]
Source: https://blog.torproject.org/landmark-hidden-services-onion-names-reserved-ietf