Internationalized Domain Name
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... RFC3490]. That is, it can contain only ASCII characters. An
implementation MAY support Internationalized Domain Names (IDNs)
using the ToASCII operation; see [RFC3490 ...
... RFC3490] for more information.
The responsibility for the conversion of internationalized domain
names to ASCII is left for the end systems, such as network access
...
... the ASCII versions of the internationalized domain names. This
provides a canonical representation, ensures that intermediate
...