diff --git a/docs/04-certificate-authority.md b/docs/04-certificate-authority.md
index 47f01e3..e9ce114 100644
--- a/docs/04-certificate-authority.md
+++ b/docs/04-certificate-authority.md
@@ -2,6 +2,9 @@
 
 In this chapter, you will provision a [PKI Infrastructure](https://en.wikipedia.org/wiki/Public_key_infrastructure) using CloudFlare's PKI toolkit, [cfssl](https://github.com/cloudflare/cfssl), then use it to bootstrap a Certificate Authority, and generate TLS certificates for the following components: etcd, kube-apiserver, kube-controller-manager, kube-scheduler, kubelet, and kube-proxy.
 
+**All procedures in this chapter should be done in `client-1`.**
+
+
 ## Certificate Authority
 
 In this section you will provision a Certificate Authority that can be used to generate additional TLS certificates.