The draft points out that the R6RS definition of string-titlecase in

terms of char-titlecase is incorrect, however, it doesn't give the

means to implement string-titlecase correctly.  char-titlecase is

not only insufficient for the task, but unnecessary.  A sufficient

utility might be char-titlecase* from Chicken's utf8 egg which

returns either a character or string if needed.

This is the reason I argued against the char-oriented case

procedures in R6RS - they not only aren't useful for correct

Unicode casing implementations, they actively encourage

incorrect ones.  I won't argue against their inclusion if you

want them for backwards compatibility, but in that case we

should provide the missing pieces.

-- 

Alex