> On Feb 3, 2017, at 1:59 PM, Wei Chuang <weihaw@xxxxxxxxxx> wrote: > > The document calls for SmtpUtf8Name to use U-labels or NR-LDH ASCII labels > for domain but not A-labels. We got advice to minimize alternative domain > forms as some implementations have had bugs doing the transform. We chose > U-labels to be consistent as the local-part is already UTF8 form and to > simplify implementations. The document recommends that SmtpUtf8Name only > be used when the local-part requires UTF8 and otherwise use rfc822Name. Can you clarify what this means for addresses such as: U: ietf-dane@духовный.org A: ietf-dane@xxxxxxxxxxxxxxxxxxxx The local part is all ASCII, so should the "U" or "A" variant be used? -- Viktor.