Truck glitch
Exclusive to Ruby and Sapphire:
256x item selling price glitch | Amazing Trainers | Berry glitch | Draining hitpoints animation glitch | Evolution animation glitch | Sticky Hold glitch | Mossdeep City Skitty glitch | Truck glitch | Nightmare glitch | Mossdeep City Skitty glitch
Acro Bike instability glitches (Japanese only) | Dark red selector glitch (International only) | Excessive doll arrangement glitch (Japanese only) | Mail and Trick glitches (Japanese only) | Surf on land (Japanese only)
Exclusive to FireRed and LeafGreen:
Celadon City origin glitch | Pokédex species glitch | Roaming Pokémon Roar glitch
Exclusive to Emerald:
Battle Pike poison knockout glitch | Black curtains glitch | Mart worker glitch | Mover Vigoroth cry glitch (Japanese only)
In various or all entries:
Azurill gender glitch | Boss HP recruit glitch (Mystery Dungeon) | Decamark-specific glitches | Dewford Gym footprint glitch | Evolution move-learning glitch | Focus Punch glitch | Roaming Pokémon IV glitch | Sky Pillar glitch | Thunderbolt glitch | VBlank RNG interrupt glitch
Not to be confused with the S.S. Anne Ship Truck.
Truck glitch is a minor glitch in Pokémon Ruby and Sapphire Versions, but not in Emerald. It makes the "Littleroot Town" title appear when saving and reseting the game inside the truck, making it get quickly cut due to the other events after the player leaves the truck.
Explanation
Once you save and reload your game inside the truck, the game does not load the script that prevents the new area's name to be shown, making the game act as like you left, for example, a normal house from Littleroot Town, where the title is normally shown.