I was cleaning out some bookmarks and found this stage listing from the game's code https://hastebin.com/kakebenili.css . I noticed all the codenames and thought it'd be neat to have them all in one spot? Some of them are interesting, I think.
The order doesn't quite line up with the displayed order either in Ultimate or their respective games, so I assume that's hold over from the older internal listings.
It's a bit surprising the 2 boxing Rings are, internally, 2 separate stages.
And laughing a bit at Brinstar being "ZebesDX" while Corneria is still Corneria
Battlefield is BattleField
Big Battlefield is Battlefield_L
Final Destination is End
Peach's Castle is Castle
Kongo Jungle is Jungle
Hyrule Castle is Hyrule
Super Happy Tree is Story
Dream Land is Pupupu64 (Dream Land's japanese name)
Saffron City is Yamabuki (Saffron's japanese name)
Mushroom Kingdom is Past64
Princess Peach's Castle is CastleDX(DX is Melee's japanese name)
Rainbow Cruise is Rainbow
Kongo Falls is Waterfall
Jungle Japes is Lodge
Great Bay is Greatbay
Temple is Temple
Yoshi's Story is Cartboard
Yoshi's Island (Melee) is Yoster
Fountain of Dreams is Fountain
Green Greens is Greens
Corneria is Corneria
Venom is Venom
Brinstar is ZebesDX
Onett is Onett
Pokemon Stadium is Stadium
Brinstar Depths is Kraid
Fourside is Fourside
Big Blue is Bigblue
Mushroom Kingdom II is PastUSA
Delfino Plaza is Dolpic
Yoshi's Island is Island
Lylat Cruise is LylatCruise
Bridge of Eldin is Oldin
Smashville is Village
Skyworld is SkyWorld
Castle Siege is Siege
WarioWare Inc is Madein
Pokemon Stadium 2 is Stadium2
Halberd is Halberd
Shadow Moses Island is Shadowmoses
New Pork City is Newpork
Summit is Top
Norfair is Norfair
Figure 8 Circuit is CircuitX (X is Brawl's japanese name)
Frigate Orpheon is Orpheon
Distant Planet is Planet
Mushroomy Kingdom is PastX
Port Town Aero Drive is Porttown
Luigi's Mansion is LuigiMansion
Pirate Ship is Pirates
Spear Pillar is Tengam (Japanese name for Coronet)
75m is 75m
Mario Bros. is MarioBros
Hanenbow is Plankton
Green Hill Zone is Greenhill
3D Land is 3DLand
Golden Plains is NewBros2
Paper Mario is Paper
Gerudo Valley is Gerudo
Spirit Train is Train
Unova Pokemon League is Unova
Prism Tower is Tower
Arena Ferox is Arena
Reset Bomb Forest is Uprising
Tortimer Island is Island
Boxing Ring (Smash) is PunchOutSB
Boxing Ring (PO) is PunchOutW
Gaur Plains is Gaur
Living Room is Nintendogs
Find Mii is StreetPass
Tomodachi Life is Tomodachi
Pictochat 2 is Pictochat2
Wily's Castle is Wily
Magicant is Magicant
Dream Land GB is Gameboy
Balloon Fight is BalloonFight
Mute City SNES is Mutecity3DS
Mushroom Kingdom U is Uworld
Mario Galaxy is Galaxy
Mario Circuit is CircuitFor
Skyloft is Skyward
Great Cave Offensive is Cave
Kalos Pokemon League is Kalos
Colosseum is Colloseum
Palutena's Temple is Angeland
Gamer is Gamer
Garden of Hope is Garden
Town & City is City
Wii Fit Studio is WiiFit
Wrecking Crew is WreckingCrew
Pilotwings is Pilotwings
Wuhu Island is WufuIsland
Windy Hill Zone is Windyhill
Pac-Land is Land
Flat Zone X is FlatZoneX
Duck Hunt is DuckHunt
Suzaku Castle is Suzaku
Super Mario Maker is Mario Maker
Midgar is Midgar
Umbra Clock Tower is Clock
Moray Towers is Parking
Dracula's Castle is Castle
Great Plateau Tower is Tower
New Donk City Hall is Odyssey
Big Battlefield is Battlefield_L
Final Destination is End
Peach's Castle is Castle
Kongo Jungle is Jungle
Hyrule Castle is Hyrule
Super Happy Tree is Story
Dream Land is Pupupu64 (Dream Land's japanese name)
Saffron City is Yamabuki (Saffron's japanese name)
Mushroom Kingdom is Past64
Princess Peach's Castle is CastleDX(DX is Melee's japanese name)
Rainbow Cruise is Rainbow
Kongo Falls is Waterfall
Jungle Japes is Lodge
Great Bay is Greatbay
Temple is Temple
Yoshi's Story is Cartboard
Yoshi's Island (Melee) is Yoster
Fountain of Dreams is Fountain
Green Greens is Greens
Corneria is Corneria
Venom is Venom
Brinstar is ZebesDX
Onett is Onett
Pokemon Stadium is Stadium
Brinstar Depths is Kraid
Fourside is Fourside
Big Blue is Bigblue
Mushroom Kingdom II is PastUSA
Delfino Plaza is Dolpic
Yoshi's Island is Island
Lylat Cruise is LylatCruise
Bridge of Eldin is Oldin
Smashville is Village
Skyworld is SkyWorld
Castle Siege is Siege
WarioWare Inc is Madein
Pokemon Stadium 2 is Stadium2
Halberd is Halberd
Shadow Moses Island is Shadowmoses
New Pork City is Newpork
Summit is Top
Norfair is Norfair
Figure 8 Circuit is CircuitX (X is Brawl's japanese name)
Frigate Orpheon is Orpheon
Distant Planet is Planet
Mushroomy Kingdom is PastX
Port Town Aero Drive is Porttown
Luigi's Mansion is LuigiMansion
Pirate Ship is Pirates
Spear Pillar is Tengam (Japanese name for Coronet)
75m is 75m
Mario Bros. is MarioBros
Hanenbow is Plankton
Green Hill Zone is Greenhill
3D Land is 3DLand
Golden Plains is NewBros2
Paper Mario is Paper
Gerudo Valley is Gerudo
Spirit Train is Train
Unova Pokemon League is Unova
Prism Tower is Tower
Arena Ferox is Arena
Reset Bomb Forest is Uprising
Tortimer Island is Island
Boxing Ring (Smash) is PunchOutSB
Boxing Ring (PO) is PunchOutW
Gaur Plains is Gaur
Living Room is Nintendogs
Find Mii is StreetPass
Tomodachi Life is Tomodachi
Pictochat 2 is Pictochat2
Wily's Castle is Wily
Magicant is Magicant
Dream Land GB is Gameboy
Balloon Fight is BalloonFight
Mute City SNES is Mutecity3DS
Mushroom Kingdom U is Uworld
Mario Galaxy is Galaxy
Mario Circuit is CircuitFor
Skyloft is Skyward
Great Cave Offensive is Cave
Kalos Pokemon League is Kalos
Colosseum is Colloseum
Palutena's Temple is Angeland
Gamer is Gamer
Garden of Hope is Garden
Town & City is City
Wii Fit Studio is WiiFit
Wrecking Crew is WreckingCrew
Pilotwings is Pilotwings
Wuhu Island is WufuIsland
Windy Hill Zone is Windyhill
Pac-Land is Land
Flat Zone X is FlatZoneX
Duck Hunt is DuckHunt
Suzaku Castle is Suzaku
Super Mario Maker is Mario Maker
Midgar is Midgar
Umbra Clock Tower is Clock
Moray Towers is Parking
Dracula's Castle is Castle
Great Plateau Tower is Tower
New Donk City Hall is Odyssey
It's a bit surprising the 2 boxing Rings are, internally, 2 separate stages.
And laughing a bit at Brinstar being "ZebesDX" while Corneria is still Corneria