The following explains the ROM naming codes you may see in game filenames, what they mean, and how to interpret them safely. These codes are not MustardOS specific. They originate from long standing ROM scene conventions and are widely used across archives, collections, and emulation communities.
This is a brief summary of the most commonly seen codes, check out the original source of information from GoodTools.
What Are ROM Codes?
ROM codes are short tags added to filenames to describe:
- Dump quality
- Region or country
- Language support
- Special hardware formats
- Hacks, fixes, or translations
They help identify what kind of ROM you are dealing with without needing to inspect it manually.
Standard ROM Codes
These are the most common tags you will encounter.
| Code | Meaning |
|---|---|
[a] |
Alternate version |
[b] |
Bad dump |
[f] |
Fixed |
[h] |
Hack |
[o] |
Overdump |
[p] |
Pirate |
[t] |
Trained |
[T-] |
Old translation |
[T+] |
New translation |
[!] |
Verified good dump |
(M#) |
Multilanguage (number of languages) |
(###) |
Checksum |
(??k) |
ROM size |
(-) |
Unknown year |
ZZZ_ |
Unclassified |
(Unl) |
Unlicensed |
Standard Code Meaning
Alternate [a]
An alternate release of the same game.
Often re-released to fix bugs, change headers, or remove things like Game Genie support.
Bad dump [b]
The ROM was dumped incorrectly.
Common causes:
- Faulty dumping hardware
- Bad cartridge connections
- Corrupted uploads
These should generally be avoided.
Fixed [f]
The ROM was modified so it:
- Runs correctly on emulators or copiers
- Works around hardware quirks
Usually safe, but not always original.
Hack [h]
The ROM has been altered.
This can include:
- Header changes
- Region unlocks
- Cheats
- Intro screens
- Gameplay hacks
Quality varies widely.
Overdump [o]
The dump contains extra meaningless data beyond the real cartridge size.
This data is normally stripped in clean dumps.
Trainer [t]
Includes a cheat menu that runs before the game starts.
Verified good dump [!]
A confirmed, clean, accurate dump.
These are generally the preferred versions.
Special System Specific Codes
These tags apply to specific consoles or formats.
Super Nintendo (SNES)
| Code | Meaning |
|---|---|
(BS) |
Broadcast Satellaview |
(ST) |
Sufami Turbo |
(NP) |
Nintendo Power |
(BS) - Games broadcast via satellite in Japan. Often time-limited or episodic.
(ST) - Uses the Sufami Turbo add-on which allowed two mini-cartridges to combine into a game.
(NP) - Distributed via Nintendo Power kiosks, mostly Japan-exclusive.
Sega Genesis / Mega Drive
| Code | Meaning |
|---|---|
(1) |
Japan & Korea compatible |
(4) |
USA & Brazil NTSC |
(5) |
NTSC only |
(8) |
PAL only |
(B) |
Non-USA systems |
[c] |
Known checksum issues |
[x] |
Bad checksum |
[R-] |
Country list |
Game Boy
| Code | Meaning |
|---|---|
[C] |
Game Boy Color |
[S] |
Super Game Boy |
[BF] |
Bung Fix |
Bung Fix [BF] - Some games needed fixes to run on Bung programmable cartridges.
Game Boy Advance (GBA)
| Code | Meaning |
|---|---|
[hI??] |
Intro hack |
Atari
| Code | Meaning |
|---|---|
(PAL) |
European PAL version |
ColecoVision
| Code | Meaning |
|---|---|
(Adam) |
ADAM computer version |
NeoGeo Pocket
| Code | Meaning |
|---|---|
[M] |
Mono sound only |
NES / Famicom
| Code | Meaning |
|---|---|
(PC10) |
PlayChoice-10 |
(VS) |
Versus System |
[hFFE] |
FFE copier format |
PlayChoice-10 (PC10) - Arcade cabinets that ran NES games with timed play.
Versus (VS) - Arcade versions designed for competitive multiplayer.
PlayStation
| Code | Meaning |
|---|---|
SCES |
Published by Sony Computer Entertainment Europe |
SCED |
SCEE-published demos |
SLES |
Third/second-party published games |
SLED |
Third/second-party published demos |
PBPX |
Some pack-in demos |
Country and Region Codes
| Code | Region |
|---|---|
(J) |
Japan |
(U) |
USA |
(E) |
Europe |
(A) |
Australia |
(UK) |
England |
(F) |
France |
(G) |
Germany |
(I) |
Italy |
(S) |
Spain |
(SW) |
Sweden |
(NL) |
Netherlands |
(FC) |
French Canadian |
(FN) |
Finland |
(GR) |
Greece |
(HK) |
Hong Kong |
(K) |
Korea |
(C) |
China |
(PD) |
Public Domain |
(Unk) |
Unknown country |
(Unl) |
Unlicensed |
Some systems (notably Genesis) reuse region codes differently depending on header formats.
What Should Be Used?
As a general guideline:
- Prefer
[!]verified good dumps - Avoid
[b]bad dumps - Be cautious with
[h],[t], and[f]unless you know why you want them - Region
(U)or(E)is usually safest unless you need a specific language
Original Text
..................
...............: STANDARD CODES ::...............
: :\
: [a] Alternate [p] Pirate :\
: [b] Bad Dump [t] Trained :\
: [f] Fixed [T-] Old Translation :\
: [T+] New Translation :\
: [h] Hack (-) Unknown Year :\
: [o] Overdump [!] Verified Good Dump :\
: (M#) Multilanguage (# of Languages) :\
: (###) Checksum (??k) ROM Size :\
: ZZZ_ Unclassified (Unl) Unlicensed :\
:...............................................:\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
.................
................: SPECIAL CODES ::...............
: :\
: .-----Gameboy-----. .----Super Nintendo----. :\
: [ [C] Color ] [ (BS) BS ROMs ] :\
: [ [S] Super ] [ (ST) Sufami Turbo ] :\
: [ [BF] Bung Fix ] [ (NP) Nintendo Power ] :\
: `-----------------' `----------------------' :\
: .--------Atari---------. :\
: .-----Genesis-----. [ (PAL) Euro Version ] :\
: [ (1) Japan ] `----------------------' :\
: [ (4) USA ] .---------GBA----------. :\
: [ (5) NTSC Only ] [ [hI??] Intro hacks ] :\
: [ (8) PAL Only ] `----------------------' :\
: [ (B) non USA ] .--------Coleco--------. :\
: [ [c] Checksum ] [ (Adam) ADAM Version ] :\
: [ [x] Bad Checksum] `----------------------' :\
: [ [R-] Countries ] :\
: `-----------------' :\
: .--------NES/FC--------. :\
: .--NeoGeo Pocket--. [ (PC10) PlayChoice 10 ] :\
: [ [M] Mono Only ] [ (VS) Versus ] :\
: `-----------------' [ [hFFE] FFE Copier fmt] :\
: `----------------------' :\
:...............................................:\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
.................
................: COUNTRY CODES ::...............
: :\
: (1) Japan & Korea (4) USA & BrazilNTSC :\
: (A) Australia (J) Japan :\
: (B) non USA (Genesis) (K) Korea :\
: (C) China (NL) Netherlands :\
: (E) Europe (PD) Public Domain :\
: (F) France (S) Spain :\
: (F) World (Genesis) :\
: (FC) French Canadian (SW) Sweden :\
: (FN) Finland (U) USA :\
: (G) Germany (UK) England :\
: (GR) Greece (Unk) Unknown Country :\
: (HK) Hong Kong (I) Italy :\
: (H) Holland (Unl) Unlicensed :\
:...............................................:\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
.......................
.............: STANDARD CODE NOTES ::............
: :\
: [a] This is simply an alternate version of a :\
: ROM. Many games have been re-released to :\
: fix bugs or even to eliminate Game Genie :\
: codes (Yes, Nintendo hates that device). :\
: ------------------- :\
: [b] A bad dump often occurs with an older :\
: game or a faulty dumper (bad connection). :\
: Another common source of [b] ROMs is a :\
: corrupted upload to a release FTP. :\
: ------------------- :\
: [f] A fixed game has been altered in some way :\
: so that it will run better on a copier :\
: or emulator. :\
: ------------------- :\
: [h] Something in this ROM is not quite as it :\
: should be. Often a hacked ROM simply has :\
: a changed header or has been enabled to :\
: run in different regions. Other times it :\
: could be a release group intro, or just :\
: some kind of cheating or funny hack. :\
: ------------------- :\
: [o] An overdumped ROM image has more data :\
: than is actually in the cart. The extra :\
: information means nothing and is removed :\
: from the true image. :\
: ------------------- :\
: [t] A trainer is special code which executes :\
: before the game is begun. It allows you :\
: to access cheats from a menu. :\
: ------------------- :\
: [!] Verified good dump. Thank God for these! :\
:...............................................:\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
......................
.............: SPECIAL CODE NOTES ::.............
: :\
: **** SNES **** :\
: (BS) These Japanese ROMs were distributed :\
: through a satellite system in Japan :\
: known as the Broadcast Satellaview. :\
: They were transmitted along with a TV :\
: show which was connected to the game in :\
: some way. These games were only playable :\
: during the show, and thus stop after an :\
: hour, and many were timed so that only :\
: certain time periods were playable. :\
: ------------------- :\
: (ST) The Sufami Turbo device allowed two :\
: GameBoy sized carts to be plugged into :\
: the SNES. Certain carts combined into :\
: new games much like the Sonic & Knuckles :\
: lock-on technology by Sega. :\
: ------------------- :\
: (NP) Nintendo Power has been known to release :\
: games only available to its subscribers. :\
: Most of these ROMs are Japanese, as this :\
: practice occured mainly in Japan. :\
: ------------------- :\
: :\
: **** Genesis **** :\
: (1) Carts with this code will run on both :\
: Japanese and Korean machines. :\
: ------------------- :\
: (4) While this code is technically the same :\
: as a (U) code, it is a newer header :\
: format and represents that the cart will :\
: run on USA and Brazil NTSC machines. :\
: ------------------- :\
: (B) This country code indicates that the :\
: cart will run on any non US machine. :\
: ------------------- :\
: [c] This code represents a cart with known :\
: faulty checksum routines. :\
: ------------------- :\
: :\
: **** GameBoy **** :\
: [BF] Bung released a programmable cartridge :\
: compatable with the GameBoy which could :\
: hold any data you wished to play. :\
: However, many games do not function on :\
: Bung v1.0 carts and have to be 'fixed'. :\
: ------------------- :\
: :\
: **** Nintendo **** :\
: PC10 The PlayChoice 10 was an arcade unit :\
: which played exact copies of NES games :\
: in an arcade cabinet. The machines had a :\
: choice of 10 games to choose from and :\
: ran for about 3 minutes on 25 cents. :\
: ------------------- :\
: :\
: VS The Versus system ran on similar hard- :\
: ware to the PC10 machines, but simply :\
: allowed you to play against each other. :\
:...............................................:\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\