Eric Sunshine [off-list ref] writes:

So, for the commit message, perhaps simply:

    Extend the shell-scripting section of CodingGuidelines to suggest
    octal escape sequences (e.g. "\302\242") over hexadecimal
    (e.g. "\xc2\xa2") since the latter can be a source of portability
    problems.

As for the change to CodingGuidelines, this would probably be sufficient:

    Use octal escape sequences (e.g. "\302\242"), not hexadecimal
    (e.g. "\xc2\xa2"), since the latter is not portable across some
    commands, such as `printf`, `sed`, `tr`, etc.

I'd prefer singling out `printf`, actually, and not talking about
"across some commands".

As I said in a separate message, we certainly do *not* want to rely
on `echo` interpreting bs-escaped octal sequences without '-e', even
though it may be expected on a POSIX systems, because it is not
portable across systems our users commonly encounter.

And `printf` has been what we chose to turn bs-escaped octal
sequence into binary.  I'd prefer not having to even worry about
`sed`, `tr`, etc. behaving differently and not allowing to expect
these other commands to be usable for turning bs-escaped octal
sequence into binary would be one way to achieve that goal.

Thanks.