Region Coding is a part of the DVD spec which divides the world into 8 regions:
Region 1: U.S., Canada, U.S. Territories
Region 2: Japan, Europe, South Africa, and Middle East (including Egypt)
Region 3: Southeast Asia and East Asia (including Hong Kong)
Region 4: Australia, New Zealand, Pacific Islands, Central America, Mexico, South America, and the Caribbean
Region 5: Eastern Europe (Former Soviet Union), Indian subcontinent, Africa, North Korea, and Mongolia
Region 6: China
Region 7: Reserved
Region 8: Special international venues (airplanes, cruise ships, etc.)
Region Free DVD - Zone Free Blu-ray (Plays ALL Blu-rays) pro kit. This is a modification for the OPPO UDP-203 Blu-ray player. After, installation it will enable the player to show movies from a different region. This means for example that a region 1 movie will play on a region 2 player, without giving the region code or protection error. Supports All DVD, Blu-ray Regions/Zone and Regional Coding enhancement (RCE).
Regional Coding Enhancement (RCE) is an additional layer of protection that some studios have placed on select REGION 1 DVDs to prevent them from playing on region-free or multi-region players.