Wikipedia
.hm
.hm is an Internet country code top-level domain ( ccTLD). Ostensibly, the domain is reserved for the Heard and McDonald Islands, uninhabited islands in the southern Indian Ocean that are under the sovereign control of Australia; Australia instead uses an .aq domain for its sites related to Heard and McDonald Islands.
Registration is directly at the second level and is managed by the HM Domain Registry; any entity can register a .hm domain.