Hi folks,
RFC3492 contained a mixed-case annotation feature which, though not
used in IDNA2003, may affect the IDNA2008 specs. In particular, basic
code points ([a-z]) that are left unencoded in punycode may be
substituted in upper case, and the result of ToUnicode operation will
preserve them. For example,
ToUnicode("xn--RSUM-bpad.com") = "RéSUMé.com"