diff --git a/CLAUDE.md b/CLAUDE.md
index f621c1f..41b8110 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -105,7 +105,8 @@ inventories/
 
 Host groups: `all`, `control`, `docker_hosts`, `proxmox_hosts`
 
-(`control` holds the one manually-provisioned control node — see ADR-009.)
+(`control` holds `ubongo`, the one manually-provisioned **physical** control node
+outside the cluster — see ADR-009 and ADR-015.)
 
 ---
 
@@ -197,6 +198,7 @@ Single-contributor, trunk-based (no merge requests / approval gates):
 | Toolchain choices      | `docs/decisions/003-toolchain.md`     |
 | Docker & Compose model | `docs/decisions/004-docker-model.md`  |
 | Bootstrapping hosts    | `docs/decisions/005-bootstrapping.md` |
+| Control / AI-worker host (`ubongo`) | `docs/decisions/015-control-host.md` |
 | Terraform              | `docs/decisions/006-terraform.md`     |
 | Network topology       | `docs/decisions/007-network.md`       |
 | Testing methodology    | `docs/decisions/008-testing.md`       |