diff --git a/README.md b/README.md
index ea0f885..04b5388 100644
--- a/README.md
+++ b/README.md
@@ -26,3 +26,7 @@
 ├── modules/                         # Terraform modules
 └── root.hcl                         # Root configuration file (provider, backend, etc.)
 ```
+
+## Host numbering
+
+The `nxvm` host numbers are a single estate-wide sequence. 2130-2133 are taken by terraform-binarylane (ausyd2nxvm2130/2131, aubne1nxvm2132/2133), so the next incus VM is 2134.