If the character following the backslash is an ASCII letter or an ASCII digit,
then the sequence may be special; if so, it's listed below. A few letters have
-not been used yet, and escaping them with a backslash is safe for now, but a
-future version of Perl may assign a special meaning to it. However, if you
-have warnings turned on, Perl will issue a warning if you use such a sequence.
-[1].
+not been used yet, so escaping them with a backslash doesn't change them to be
+special. A future version of Perl may assign a special meaning to them, so if
+you have warnings turned on, Perl will issue a warning if you use such a
+sequence. [1].
It is however guaranteed that backslash or escape sequences never have a
punctuation character following the backslash, not now, and not in a future
Mnemonic: Complement of I<\n>.
=item \R
+X<\R>
C<\R> matches a I<generic newline>, that is, anything that is considered
a newline by Unicode. This includes all characters matched by C<\v>
metacharacter, and suggests C<\R> as the notation.
=item \X
+X<\X>
This matches a Unicode I<extended grapheme cluster>.