\u vs \U

[Peter F. Patel-Schneider]

"Characters in the range from U+0000 to U+001F and U+007F (DEL) that are not represented using ECHAR MUST be represented by UCHAR."

It appears to me that U+1 can be written as either \u0001 or \U00000001.

[Ted Thibodeau Jr]

That appears to be the case for all \u0000–\uFFFF, that they can also be written as \U00000000–\U0000FFFF, respectively. That does pose a quandary.

[Gregg Kellogg]

This does require clarification. Perhaps with something like “using the shortest possible ECHAR representation”. It would want some tests, too.