Comment 1 for bug 1499473

Well, I made some more research: I think this can be closed as

WON'T FIX

This seem to be a feature (not a bug) to comply exactly to POSIX, **nothing more**.

Here is the related POSIX documentation:
http://www.unix.com/man-page/POSIX/1posix/printf/

It specifies octal escaping, and it also explains that Hexadecimal escaping can be ambiguous (the explanation is far fetched!)

So ash might have added the \x but dash removed it (probably) to be strictly POSIX to the minimum.

Also, we don't have \u or \U escaping for Unicode.

If you need \x, \u or \U, the workaround is to use the GNU printf instead of the builtin.

Sorry for the inconvenience;