Large storage box byte shift glitch
0x1500 control code arbitrary code execution (Crystal) | Cart-swap arbitrary code execution | Generation I custom map script pointer | Generation I invalid meta-map scripts | Generation I item ("8F", "ws m", "-g m", "5かい", "てへ" etc.) | Generation I move ("-", "TM42") | Generation I Trainer escape glitch text boxes | Generation II bad clone | Generation II Burned Tower Silver | Japanese Crystal Pokémon Communication Center SRAM glitches | Coin Case glitch | Generation II glitch Pokédex sortings | Pikachu off-screen glitch ACE | OAM DMA hijacking | Pikachu glitch emote | Generation III glitch Pokémon summary | Generation III glitch move animation) | Remote code execution | TM/HMs outside of the TM/HM pocket | ZZAZZ glitch Trainer FC
Cloning | Item duplication glitch (Generation I) | Pokémon merge glitch ("Q Glitch", Generation I) | Time Capsule exploit | Bug-Catching Contest data copy glitch (Generation II, Japan only) | Berry glitch | Battle Tower Lati@s glitch (Generation III) | (Mimic) Transform Rage glitch (Generation IV)
Transform held item glitch (Generation IV, Japan only) | Mimic glitch (Generation IV, Japan only)
99 item stack glitch | LOL glitch | Rival LOL glitch | Instant LOL glitch | RAM LOL glitch | Out of bounds LOL glitch | blockoobLG | Instant encounter infinite chain glitch | LGFly | Super Glitch (Generation I) | Party remaining HP glitch | Super Glitch (Generation III) | Text pointer manipulation mart buffer overflow glitch | CoolTrainer♀-type move | Double distort CoolTrainer♀ corruption | Yami Shop glitch | Party Pokémon box data shift glitch | Unterminated name glitch item instant encounter (Japanese Red/Green)
Item stack duplication glitch (Generation I)
Generation I expanded items pack (Glitch Rocket HQ maps, Map FE (English and non-English European Yellow) | Map script pointer manipulation (arbitrary code execution | Map script pointer item ball manipulation) | Text pointer manipulation (arbitrary code execution | Item ball manipulation | Mart buffer overflow) | Trainerless instant encounter glitch
Bad clone glitch (Generation II)
????? party overloading (Type 0xD0 move glitch | ????? map corruption | Celebi trick | Celebi Egg trick | Shiny Celebi trick | Glitch move map corruption | Overloaded party map corruption | Glitch Unown (Glitch Unown map corruption) | Duplicate key items glitch (Infinite items and item creation, Expanded Balls pocket (Wrong pocket TM/HMs, Glitch Pokédex categories))
Closed menu Select glitches (Japanese Red/Green)
Dokokashira door glitch (International) | Fossil conversion glitch (international) | Second type glitch | Skip to Level 100 glitch | Trainer mutation glitch | Walk through walls (International) | Lift glitch | Badge describer glitch
Pomeg glitch (Generation III)
Pomeg data corruption glitch ("Glitzer Popping") | Charm glitch
Voiding (Generation IV)
Broken escalator glitch (Japan only) | Elite Four door glitch (Japan only)
2x2 block encounter glitches (Generation I)
Left-facing shore tile glitch (in-game trade shore encounter trick, Old man trick, Trade link up shore encounter trick, Fight Safari Zone Pokémon trick) | Viridian Forest no encounter grass tiles glitch
Safari Zone exit glitch | RAM manipulation | Out of bounds Glitch City (Generation II) | Slowpoke Well out of bounds corruption (French Gold/Silver/Crystal)
Large storage box byte shift glitch
Storage box remaining HP glitch | Generation I max stat trick
Generation I save corruption | 255 Pokémon glitch | Expanded party encounter table manipulation (Generation I) | Send party Pokémon to a new game (Generation I) | Generation II save corruption | Mailbox glitches | Mystery Gift item corruption | Trainer House glitches
Death-warp | Ditto trick | Experience underflow glitch | Mew trick | Text box ID matching | Meta-map script activation
Ledge method | Museum guy method | Rival's effect | Select glitch method (International Select glitch method), Brock Through Walls
Grass/rock Surfing glitch (Spanish/Italian only) (adaptions: Submerge glitch (international)) | 8 8 (0x7C) grass/rock surfing glitch (English Red/Blue))
The large storage box byte shift glitch is a major glitch in Pokémon Red, Blue, and Yellow and the parent glitch of remaining HP glitch and Generation I maximum stat glitch.
Summary
The large storage box byte shift glitch involves a storage box and the glitch Pokémon 'M (FF) or Q.
This glitch lets you shift bytes upwards for stored Pokémon in the box data structure thanks to the removal of the end list terminator and a value such as catch rate (remaining HP glitch) or remaining PP (Generation I maximum stat glitch) acting as an artificial FF terminator.
The glitch was found by Paco81 and verified by ciel4, and together they found new information about the nature of the glitch. The glitch was later researched by Torchickens.
While the most simple thing you can do with the glitch is change the index number (specifically the recipient byte) of a Pokémon by taking it from its remaining HP, as demonstrated by Paco81 you can create custom Pokémon with custom types or as demonstrated by uacdario, shiny Pokémon.
The glitch also only works for box 1 on real hardware in a box that was never completely full (has less than 20 Pokémon). Boxes other than 1 are filled with FF bytes making this glitch impossible on those boxes.