[1] .onion - Wikipedia, the free encyclopedia ( ( 版)) <http://en.wikipedia.org/wiki/.onion>

[2] RFC 7686 - The ".onion" Special-Use Domain Name ( 版) <https://tools.ietf.org/html/rfc7686>

[3] IETF では >>2提案標準となっていますが、 IANATLD の一覧には現時点では掲載されていないようです。

>>5 の方には登録されています。
[4] .onion | IETF Blog ( 版) <https://www.ietf.org/blog/2015/09/onion/>

In effect, ‘.onion’ will be treated in the same way .local, .localhost, and .example have been dealt with previously—that is, outside the global Domain Name System (DNS). Adding .onion to the Special-Use Domain Names registry will also enable hosts on the Tor network to obtain validated SSL certificates.

[5] Special-Use Domain Names ( 版) <http://www.iana.org/assignments/special-use-domain-names/special-use-domain-names.xhtml>

[6] Standardize .onion DNS lookup blocking? · Issue #248 · whatwg/fetch ( 版) <https://github.com/whatwg/fetch/issues/248>

[7] Tor2web: Browse the Tor Onion Services ( ()) <https://tor2web.org/>

Whenever you see a URL like http://duskgytldkxiuqc6.onion/, that's a Tor Onion service. Just replace .onion with .onion.to or .onion.city or .onion.cab or .onion.direct or any other domain made available by volounteers Tor2web operators

[8] Nima Fatemiさんのツイート: "Firefox has introduced a new preference that blocks onion addresses on DNS level to prevent accidental leak. ⚙👌 https://t.co/islL3Y4ksd" () <https://twitter.com/mrphs/status/708548201800982528>

[9] 1228457 – Implement RFC 7686 (fail dns for .onion) () <https://bugzilla.mozilla.org/show_bug.cgi?id=1228457>

[10] 1250696 – .onion names contain their own validator, we should use that () <https://bugzilla.mozilla.org/show_bug.cgi?id=1250696>

[11] 1129618 – please add .onion to public suffix list () <https://bugzilla.mozilla.org/show_bug.cgi?id=1129618>

[12] [cabfpub] Ballot .onion ballot () <https://cabforum.org/pipermail/public/2015-February/004922.html>

[13] Add onion (#386) (sleevi著, ) <https://github.com/publicsuffix/list/commit/45a2bf8ef3e22000fbe4bfa5f9252db41d777001>