When Lando says "Go on, you pirate" his entire outfit is reversed - his shoulder holster strap goes the other way, and his rank insignia changes side too.
When filming ROTJ, Lucas didn't want anyone to find out that they were shooting the third Star Wars movie, because pandemonium could break out. So when someone asked the crew what they were filming, they said "Blue Harvest". All of the crew had shirts and hats that said Blue Harvest on them. The fictitious film's tagline was "Horror beyond imagination."