$ldqm = encode 'UTF-8', decode 'Windows-1252', encode 'UTF-8', $ldqm;

   $ldqm                 => 201C
   encode 'UTF-8'        => E2 80 9C
   decode 'Windows-1252' => 00E2 20AC 0153
   encode 'UTF-8'        => C3 A2 E2 82 AC C5 93

##</code><code>##

   $ldqm                 => C3 A2 E2 82 AC C5 93
   decode 'UTF-8'        => 00E2 20AC 0153
   encode 'Windows-1252' => E2 80 9C
   decode 'UTF-8'        => 201C

##</code><code>##

$rdqm = encode 'UTF-8', decode 'Windows-1252', encode 'UTF-8', $rdqm;

   $rdqm                 => 201D
   encode 'UTF-8'        => E2 80 9D
   decode 'Windows-1252' => 00E2 20AC ????
   [error handling]      => 00E2 20AC FFFD
   encode 'UTF-8'        => C3 A2 E2 82 AC EF BF BD

##</code><code>##

   $rdqm                 => C3 A2 E2 82 AC EF BF BD
   decode 'UTF-8'        => 00E2 20AC FFFD
   encode 'Windows-1252' => E2 80 ??
   [error handling]      => E2 80 3F
   decode 'UTF-8'        => ???? ???? 003F
   [error handling]      => FFFD FFFD 003F