c:\@Work\Perl\monks>perl -wMstrict -le
"my @cases = qw/ABA SCO ACC PHC GHF/;
 my $re = join '|', @cases;
 ;;
 for my $text ('SCO', 'ENDOSCOPE', 'Microsoft') {
   print qq{'$text' found (grep)}  if grep { $text eq $_ } @cases;
   print qq{'$text' found (regex)} if $text =~ /^$re$/;
   }
"
'SCO' found (grep)
'SCO' found (regex)
'ENDOSCOPE' found (regex)