diff --git a/CLAUDE.md b/CLAUDE.md
index 0f21af6..4c07ffe 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -67,3 +67,15 @@ adding hardening or convention that the platform already provides.
 Every service reads secrets from a sibling `.env`. Never commit one — the root
 `.gitignore` covers `.env`/`*.env` and re-includes `.env.example`. Keep
 `.env.example` in sync whenever a compose file gains or drops a variable.
+
+`.env.example` is a template for anyone, so every value in it stays generic —
+the service's own name, a placeholder domain, or an empty string. Never a real
+hostname, git identity, email, domain or account name. Personal values are set
+per deployment, in the Coolify or Dokploy environment for that app, and live
+only in the gitignored `.env`.
+
+Compose interpolation reads the deploying shell's environment before the
+`.env` file, so a variable must not share a name with anything the shell
+already exports. `HOSTNAME` is the trap: it is set inside every container,
+including the one Coolify itself runs in, and would silently win. Hence
+`SERVICE_HOSTNAME` in `code-server` and `paseo`.
diff --git a/alloy/README.md b/alloy/README.md
index 34e9a3d..2ef47ed 100644
--- a/alloy/README.md
+++ b/alloy/README.md
@@ -53,7 +53,7 @@ source, and under Fleet Management. The same token serves `remotecfg`,
 Prometheus and Loki basic-auth.
 
 ```bash
-export ALLOY_HOSTNAME=miti-jp REMOTECFG_ID=miti-jp ...
+export ALLOY_HOSTNAME=example-host REMOTECFG_ID=example-host ...
 docker compose up -d
 ```