Beta Weapons are weapons that were not included in the game. It is also includes some weapons that didn't make it to the final game and weapons have their models changed. Many made well during development and it is unknown why they were removed. However, very most of them can be obtained through Cheat Devices and trainers.
Grand Theft Auto 2
Weapons called electro-baton, instant vehicle bomb and microwave were cut. The first two have their HUD icons inside game files.