looking up unassigned characters

[Erik van der Poel]

Final question from the summary:

> B. There are few if any restrictions on the lookup phase of IDNAv2
> (and IDNA2003). The consequences are that lookup will match
> domain names injected into DNS by registries that are non-conformant
> with registration restrictions intended by the protocol specification.
> This condition arises from permitting the looking up of DISALLOWED
> or UNASSIGNED characters. How serious a problem is this in the
> view of the WG?

Actually, it's not true that IDNA2003 allows the lookup of
"prohibited" (i.e. DISALLOWED) characters. There is a flag that allows
the lookup of characters that were unassigned in Unicode 3.2.