Here is a list of common ROM tags, retrieved from the public domain. I also noted some ROM specifics to look out for and explained what they mean farther down the page.

• [!] – Verified Good Dump (These are guaranteed to be error-free)
• [b] bad dump (self-explanatory, ususally buggy, slow, or with missing sections)
• [h] hacked rom (not an illegal obtain, just something not quite right in one or more sections of the code)

• [a] – Alternate ([a1], [a2], [a3], etc. if there are more than one, still good dumps)
• [b] – Bad Dump
• [BF] – Bung Fix
• [c] – Cracked
• [f] – Other Fix
• [h] – Hack
• [o] – Overdump
• [p] – Pirate
• [t] – Trained
• [T] – Translation
• (Unl) – Unlicensed
• [x] – Bad Checksum
• ZZZ_ – Unclassified
• [!] – Verified Good Dump
• (???k) – ROM Size Special Codes:
• [C] – Color GameBoy
• [S] – Super GameBoy
• (M#) – Multilanguage (# of Languages)
• [M] – Mono Only (NeoGeo Pocket)
• (PC10) – PlayChoice 10 (NES)
• (1) – Japan (Genesis)
• (4) – USA (Genesis)
• (5) – NTSC Only (Genesis)
• ( 8 ) – PAL Only (Genesis)
• (BS) – BS ROMS (SNES)
• (ST) – Sufami Turbo (SNES)
• (NP) – Nintendo Power (SNES)
• (Adam) – ADAM Version (Coleco)
• (PAL) – PAL Video Country Codes:
• (A) – Australian
• (C) – Chinese
• (E) – Europe
• (F) – French
• (FN) – Finland
• (G) – German
• (GR) – Greece
• (HK) – Hong Kong
• (I) – Italian
• (J) – Japan
• (K) – Korean
• (NL) – Dutch
• (PD) – Public Domain
• (S) – Spanish
• (SW) – Sweden
• (U) – USA
• (UK) – England
• (Unk) – Unknown Country
• (-) – Unknown Country

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 bad ROMs is corrupted uploads, which affect all subsequent copies of the ROMs.

[f] A fixed game has been altered in some way so that it will run more efficiently on a copier or emulator.

[h] Something in this ROM is not quite right. 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 is useless and will be removed from the true image.

[t] A trainer is a special section of code which executes before the game begins. It usually allows you to access cheats from a menu.

[!] Verified good dump. Should be error-free and play perfectly!