old-style backreference (see
L</Disambiguation rules between old-style octal escapes and backreferences>
below.) You can avoid this by making the first of the three digits always a
-zero, but that makes \077 the largest ordinal unambiguously specifiable by this
-form.
+zero, but that makes \077 the largest code point specifiable.
In some contexts, a backslash followed by two or even one octal digits may be
interpreted as an octal escape, sometimes with a warning, and because of some
and vertical whitespace characters.
The exact set of characters matched by C<\d>, C<\s>, and C<\w> varies
-depending on various pragma and regular expression modifiers. See
-L<perlre>.
+depending on various pragma and regular expression modifiers. It is
+possible to restrict the match to the ASCII range by using the C</a>
+regular expression modifier. See L<perlrecharclass>.
The uppercase variants (C<\W>, C<\D>, C<\S>, C<\H>, and C<\V>) are
character classes that match, respectively, any character that isn't a