character and string escapes

[Mike Gran]

Hi-

I find this behavior curious.

guile>  (integer->char 129)
#\201

guile> (write (integer->char 129))
#\201

guile> (write (string (integer->char 129)))
"\x81"

guile> #\x81
ERROR: In procedure scm_lreadr:
ERROR: standard input:8:1: unknown character name x81
ABORT: (read-error)

Why do strings use hex for unnamed control characters while 
characters use octal?

Also, r6rs likes hex characters.  Is that something that might be
added to Guile?  

Thanks,

Mike Gran