I don't think IANA explicitly reserved .dev. It was made popular as a local dev domain by Basecamp's Pow[1] and Laravel Valet[2]. IANA only defines .test, .exam

I don't think IANA explicitly reserved .dev. It was made popular as a local dev domain by Basecamp's Pow[1] and Laravel Valet[2]. IANA only defines .test, .example, .invalid, .local, and .localhost as reserved (with .onion being the latest addition in 2015[3]) Though in this list, only .test and .example are marked as non-special and must be resolved normally by RFC 6761, and .local is reserved for mDNS by RFC 6762. In this list, .test would have been the most appropriate for Pow to use. CydeWeys (Tech Lead of Google Registry) has commented on HN in the past that they did not anticipated people weren't following the best practices[4], which makes me think IANA should have given .dev the same treatment as .onion: by explicitly reserving them (but this is another topic to discuss). [1]: https://github.com/basecamp/pow https://github.com/basecamp/pow [2]: https://github.com/laravel/valet https://github.com/laravel/valet [3]: https://www.rfc-editor.org/rfc/rfc7686.html https://www.rfc-editor.org/rfc/rfc7686.html [4]: https://news.ycombinator.com/item?id=24606714 https://news.ycombinator.com/item?id=24606714