/[a^]at/; # matches 'aat' or '^at'; here '^' is ordinary
Perl has several abbreviations for common character classes. (These
-definitions are those that Perl uses in ASCII mode with the C</a> modifier.
-See L<perlrecharclass/Backslash sequences> for details.)
+definitions are those that Perl uses in ASCII-safe mode with the C</a> modifier.
+Otherwise they could match many more non-ASCII Unicode characters as
+well. See L<perlrecharclass/Backslash sequences> for details.)
=over 4