diff --git a/README.md b/README.md
index 38f80ee..fea8079 100644
--- a/README.md
+++ b/README.md
@@ -525,7 +525,7 @@ All configuration parameters are defined via environment variables in `.env`:
 | Variable | Type | Default Value | Scope | Description |
 |---|---|---|---|---|
 | `HF_TOKEN` | `String` | *(Required)* | Backend / Docker | HuggingFace user access token with authorized permissions to download gated `facebook/sam3` weights. |
-| `VIDEO_ARCHIVE_HOST` | `Path` | `./data/archive` | Docker Compose | Host filesystem directory path containing raw CCTV video recordings (structured as `<date>/<batch>.mp4`). Mounted read-only (`:ro`). |
+| `VIDEO_ARCHIVE_HOST` | `Path` | `./data/archive` | Docker Compose | Host filesystem directory path containing raw CCTV video recordings (structured as `<date>/<batch>.mp4`). Relative paths resolve against the directory `./start.sh` runs from. Mounted read-write; written only by user-initiated upload / date-folder creation (REQ-178), nothing else. |
 | `APP_DATA_DIR` | `Path` | `./data` (or `/data` in Docker) | Backend | Base directory for application persistent data, SQLite database (`app.db`), projects, extracted frames, datasets, and model weights. |
 | `VIDEO_ARCHIVE` | `Path` | `/videos` (or `data/archive`) | Backend | Internal container/local filesystem path where the video archive is browsed by FastAPI. |
 | `WEB_PORT` | `Integer` | `9000` | Docker / Nginx | Host HTTP port mapped to the Nginx frontend web UI. |