Pokémon FireRed and LeafGreen beta
During the planning and development stages of Pokémon FireRed and LeafGreen, several parts were going to be a part of the games. Some of them were dropped or changed, but some of those dropped concepts of the prototype version can still be found in the game's programming.
Locations
The islands in the Sevii Islands region would likely be named Sevii Isles. In addition, several more locations in the Sevii Islands have been found in the programming code, including Sevii Isles 6-9 and 22-24. It is very notable that Sevii Isle 8 and 9 have fully coded map data, implying that they were scrapped very late in the game's production.
A records room has also been found, but cannot be accessed without the use of a cheating device.
Items
Key items from Ruby and Sapphire exist within FireRed and LeafGreen programming and are only obtainable through the use of a cheating device. They have little or no function at all. These items include the Mach Bike which works but only moves as fast as the regular bike, Devon Goods and HM08, both completely unusable. These items were left in because these versions were built off of the Ruby and Sapphire engine.