Besides, in networking, it's better to be conservative. You don't start with a short blacklist and then grow it when you find others. No, you start with a whitelist, and grow that.
One could even make an argument along these lines for nameprep. Perhaps nameprep should not have started with the *huge* Unicode character set, subsequently making a feeble attempt to reduce that set to a safe one.
One could make the argument that the nameprep RFC does not adhere to the old rule:
"Be liberal in what you accept, and conservative in what you send"
This is from section 1.2.2 of RFC 1122, a key RFC also known as STD 3:
http://ietf.org/rfc/rfc1122.txt
I wonder if something like this would catch the attention of the IETF or even the IESG?
Erik
