Bootlegs? I'm only talking about official Capcom releases. For instance, across this line:
sf2ua Street Fighter II: The World Warrior (USA 910206) sf2ub Street Fighter II: The World Warrior (USA 910214) sf2uc Street Fighter II: The World Warrior (USA 910306) sf2ud Street Fighter II: The World Warrior (USA 910318) sf2ue Street Fighter II: The World Warrior (USA 910228) sf2uf Street Fighter II: The World Warrior (USA 910411) sf2ui Street Fighter II: The World Warrior (USA 910522) sf2uk Street Fighter II: The World Warrior (USA 911101)