C<qr/\X/>, which matches a Unicode logical character, has been expanded to work
better with various Asian languages. It now is defined as an C<extended
grapheme cluster>. (See L<http://www.unicode.org/reports/tr29/>).
-Anything matched by previously will continue to be matched. But in addition:
+Anything matched previously that made sense will continue to be matched. But
+in addition:
=over
C<\X> will now always match at least one character, including an initial mark.
Marks generally come after a base character, but it is possible in Unicode to
have them in isolation, and C<\X> will now handle that case, for example at the
-beginning of a line or after a C<ZWSP>.
+beginning of a line or after a C<ZWSP>. And this is the part where C<\X>
+doesn't match the things that it used to that don't make sense. Formerly, for
+example, you could have the nonsensical case of an accented LF.
=item *