| blight | Mario Kart Binary Light Data |
| blk | Descent Mission Builder Block |
| blorb | Interactive Fiction Package |
| bls | Blockland Saved Game |
| blue | EVE Online Generic Data File |
| blv | Might and Magic 6 Level Geometry Data |
| bly | FIFA World Cup Game Data |
| blz | N-Gage Video Game |
| bm1 | Apogee Bio Menace Map |
| bmd | MU Online Game Data |
| bmd | Super Mario Sunshine Game Data |
| bmd6anim | Doom 4 Model Animation Data |
| bmd6model | Doom 4 Model Data |
| bme | BeatMania Song |
| bmg | Mario Kart Wii Message File |
| bmodel | Doom 4 Model Data |
| bmq | Re-Volt Texture Data |
| bms | Be-Music Script |
| bms | BeatMania Song |
| bmu | Bioware Aurora Music Unit |
| bmz | Portal Bonus Map Zip |
| bndl | Need for Speed: Most Wanted Game Bundle Data |
| bndlxml5 | Middle Earth: Shadow of Mordor Game Data |
| bni | Battle.net Icon File |
| bnk | Need for Speed: Hot Pursuit Audio Bank Data |
| bnry | The Sims 4 Game Data |
| bnt | Entropia Universe Game Archive |
| bo2 | TerrainControl Custom Biome Objects v2 |
| bo3 | TerrainControl Custom Biome Objects v3 |
| bod | X3: Reunion Ship Data |
