i scroll to the document and the various associated documents and still did not understood what is prohibited and what is going to be prohibited and the consequences for that: even if a domain stops resolving it still can have value as a peace of rarity to collectors. the drastic measure is impose the drop of the domains from the registry.
also, i still can't find what are the DISALLOWED characters.
4..2.2. Rejection of Characters that are not Permitted
The candidate Unicode string MUST NOT contain characters that appear
in the "DISALLOWED" and "UNASSIGNED" lists specified in
this leads to a site on IETF that is a drop point for documents.
there is also the case for symbols used as diacritics that must not begin a domain name:
18.104.22.168. Leading Combining Marks
The Unicode string MUST NOT begin with a combining mark or combining
character (see The Unicode Standard, Section 2.11 [Unicode] for an
and according to the Unicode standard: http://www.unicode.org/versions/Unicode5.0.0/ch02.pdf
one can have a domain name that result from the combination of
a + @¨ + u -> äu (not aü)
@¨ + a + u -> @¨au
so something like "`ab.com" should not be possible. but how about domains like ":ab.com" is permited? or "$ab.com"?
and where it is mentioned that symbols can't be used? and which symbols?