Protocol-08 (and status of Defs-04 and Rationale-06)

[Eric Brunner-Williams]

Vint,

Assuming for the moment that the "forbid in protocol" position is 
useful, there is:

4a. forbid at protocol level the mixing of Eastern Arabic-Indic, 
Arabic-Indic digits, within a label, which actually are confusable, that 
is, not 4, 5, and 6).

My view is 3, but the weakest correct position of the "confusable" and 
"in protocol" case that does not rely upon the IM bugs that map code 
points in the U+06xx range to the 0x3x range is 4.

4b, for completeness, orbid at protocol level the mixing of Eastern 
Arabic-Indic, Arabic-Indic digits, within a label, even those which are 
not confusable, that is including 4, 5, and 6.

The "unnecessary", "culturally awkward" or "ugly" and "in protocol" case is:

5. forbid at protocol level the mixing of Latin and Eastern Arabic-Indic 
and Latin and Arabic-Indic digits.

The alternate justification is the IM mapping in some applications being 
non-invertable, that is, some code point other than 0x3x is mapped to 0x3x.

The union of 4a and 4b and 5 "in protocol" are 1.

Eric