docs: surface region filtering in the readme

README.md

@@ -106,6 +106,10 @@ python scripts/generate_pack.py --platform batocera --output-dir dist/
 python scripts/generate_pack.py --emulator dolphin
 python scripts/generate_pack.py --system sony-playstation-2
 
+# One region, best first, one file per system and region
+python scripts/generate_pack.py --platform retroarch --region us,eu,jp
+python scripts/generate_pack.py --platform retroarch --region us --one-per-slot
+
 # List available emulators and systems
 python scripts/generate_pack.py --list-emulators
 python scripts/generate_pack.py --list-systems
@@ -165,4 +169,4 @@ The scripts and tooling are released under the [MIT License](LICENSE).
 The BIOS and firmware files are not covered by that license: they are third-party system software, preserved and provided for personal backup, archival, and interoperability with emulation software. [NOTICE](NOTICE) sets out their status and how to ask for a file to be removed.
 The reasoning, and where it is weakest, is in the [FAQ](https://abdess.github.io/retrobios/wiki/faq/#is-this-legal).
 
-*Auto-generated on 2026-09-04T02:08:41Z*
+*Auto-generated on 2026-09-04T05:36:10Z*

scripts/generate_readme.py

@@ -498,6 +498,10 @@ def generate_readme(db: dict, platforms_dir: str) -> str:
             "python scripts/generate_pack.py --emulator dolphin",
             "python scripts/generate_pack.py --system sony-playstation-2",
             "",
+            "# One region, best first, one file per system and region",
+            "python scripts/generate_pack.py --platform retroarch --region us,eu,jp",
+            "python scripts/generate_pack.py --platform retroarch --region us --one-per-slot",
+            "",
             "# List available emulators and systems",
             "python scripts/generate_pack.py --list-emulators",
             "python scripts/generate_pack.py --list-systems",

wiki/index.md

@@ -19,7 +19,7 @@ If you just want to download BIOS packs, see the [home page](../index.md).
 
 - **[Architecture](architecture.md)** - directory structure, data flow, platform inheritance, pack grouping, security, edge cases, CI workflows
 - **[Tools](tools.md)** - CLI reference for every script, pipeline usage, scrapers
-- **[Advanced usage](advanced-usage.md)** - custom packs, target filtering, truth generation, emulator verification, offline workflow
+- **[Advanced usage](advanced-usage.md)** - custom packs, region filtering, one file per slot, target filtering, truth generation, emulator verification, offline workflow
 - **[Verification modes](verification-modes.md)** - how each platform verifies BIOS files, severity matrix, resolution chain
 - **[Data model](data-model.md)** - database.json structure, indexes, file resolution order, YAML formats
 - **[Troubleshooting](troubleshooting.md)** - diagnosis by symptom: missing BIOS, hash mismatch, pack issues, verify errors
@@ -57,6 +57,7 @@ See [contributing](../contributing.md) for submission guidelines.
 - **scraper** - a script that fetches BIOS requirement data from an upstream source (System.dat, es_bios.xml, etc.)
 - **exporter** - a script that converts ground truth data back into a platform's native format
 - **target** - a hardware architecture that a platform runs on (e.g. switch, rpi4, x86_64, steamos)
+- **region** - the territory an emulator's code branches on to select a file; `--region` builds a pack from an ordered priority list, `--one-per-slot` keeps one file per system and region
 - **variant** - an alternative version of a BIOS file (different revision, region, or dump), stored in `.variants/`
 - **required** - a file the core needs to function; determined by source code behavior
 - **optional** - a file the core functions without, possibly with reduced accuracy or missing features