some comments about draft-ietf-idn-idna-08.txt

Hi all, 
I read the drafts about IDNA, nameprep and Punycode, and I have some doubt 
about the first one, from the point of view of a dumb reader. Ok, you 
may say that I am dumb, but nevertheless I think that some of those 
doubts may affect other people too. Could you please look at them?

Sect 3, req. 2). "An equivalent domain name". It is a *unique* equivalent
domain name, right? 

Sect. 4.1., para 4. I think that ToASCII may for example fail if I have
a sequence of code points like "ascii? yes", which contains "?" and " ".
In that case, I think that an explicit failure condition should be added
at the various steps of the algorithm (3, 5, 8)

Sect. 6.1, para 2. I am wondering if we SHOULD present both forms, if the 
ACE label is presented. It could be useful for developers, who may see 
at a glance what it's happening. Moreover, if some character may not be
displayed, you have a visual hint that the string you see is not the 
whole of the story.

Sect. 8. Why EDNS has not been included in the specifications?

As a side issue, I'd like to be pointed at some heuristic data about 
Punycode. I may imagine that its algorithms are geared towards efficient
handling of non-ideographic languages, like Devanagari, and single 
"intrusive" characters, but I would like to know more.

Ciao, .mau.