In several sections under
we have for the canonical form of a unicode_locale_id and its u extension:
"any variants in alphabetical order"
"any extensions in alphabetical order by their singleton"
"All attributes are sorted in alphabetical order."
"All keywords are sorted by alphabetical order of keys."
We should specify that all of these use Unicode code point order, which is the same as ASCII order. In particular, digits 0-9 sort before letters a-z (unlike in, say, EBCDIC).
Please also use examples with relevant subtags where those are well-formed, such as variant "1901" and singleton "4".
Note that under http://www.unicode.org/reports/tr35/tr35.html#Inheritance_and_Validity there is also "an element chain is a resolved XPath leading from the root to an element, with attributes on each element in alphabetical order"
While not related to Unicode locale IDs, I assume that this also wants to use the same sort order.