arpa
e164.arpa
home.arpa
in-addr.arpa
ip6.arpa
iris.arpa
uri.arpa
urn.arpa

// as : https://www.iana.org/domains/root/db/as.html
as
gov.as

// asia : https://www.iana.org/domains/root/db/asia.html
asia

// at : https://www.iana.org/domains/root/db/at.html
// Confirmed by registry <******@****.***> 2008-06-17
at
ac.at
co.at
gv.at
or.at
sth.ac.at