c:\@Work\Perl\monks>perl -wMstrict -le
"use 5.010;
 ;;
 for my $s (qw(XXX ppp)) {
   print qq{for '$s' string};
   if ($s !~ m{ (*F) | p | q }xms) { print '  with (*F): no match, !~ true' }
   if ($s !~ m{   Z  | p | q }xms) { print '  with Z:    no match, !~ true' }
   if ($s !~ m{        p | q }xms) { print '  no (*F):   no match, !~ true' }
   print '  -------';
   }
"
for 'XXX' string
  with (*F): no match, !~ true
  with Z:    no match, !~ true
  no (*F):   no match, !~ true
  -------
for 'ppp' string
  -------