Re: [idn] Document Status?

["Adam M. Costello" <idn.amc+0@nicemice.net.RemoveThisWord>]

Dave Crocker <dhc@dcrocker.net> wrote:

> you need to distinguish between the abstract, formal name space,
> versus the over-the-wire encoding of that name space.

Just to clarify, this is NOT a picture of the IDNA model:

    +----------+            +---------+
    |          |            |         |
    | abstract |            | encoded |
    | domain   |   <---->   | domain  |
    | labels   |            | labels  |
    |          |            |         |
    +----------+            +---------+


This is a picture of the IDNA model:

    +----------------------------+
    |  internationalized labels  |
    |                            |
    |  +----------------+        |
    |  |  ASCII labels  |        |
    |  |                |        |
    |  |  +--------+    |        |
    |  |  | ACE    |    |        |
    |  |  | labels |    |        |
    |  |  +--------+    |        |
    |  +----------------+        |
    +----------------------------+


There is only one space (internationalized labels), which has a subset
(ASCII labels), which has a subsubset (ACE labels).  The non-ASCII
labels (in the outer ring) are unsuitable for use in IDN-unaware
protocols/formats/interfaces, and the ACE labels (in the center) are
unsuitable for display to users.  Fortunately, there is an equivalence
relation between the non-ASCII labels and the ACE labels, so if you ever
find yourself with a label you can't use, there is an equivalent label
you can use instead.

AMC