Perl tries really hard to work both with Unicode and the old
byte-oriented world. Most often this is nice, but sometimes Perl's
-straddling of the proverbial fence causes problems. Here's an example
-of how things can go wrong. A locale can define a code point to be
-anything it wants. It could make 'A' into a control character, for example.
-But strings encoded in utf8 always have Unicode semantics, so an 'A' in
-such a string is always an uppercase letter, never a control, no matter
-what the locale says it should be.
+straddling of the proverbial fence causes problems.
=back