diff --git a/README.md b/README.md
index 603a767..c717273 100644
--- a/README.md
+++ b/README.md
@@ -22,13 +22,15 @@ Kubernetes is an open‑source platform that automates the deployment, scaling,
   - [Manifest - StringData](#manifest---stringdata)
   - [Inline with heredoc and environment variables](#inline-with-heredoc-and-environment-variables)
   - [substr](#substr)
-  - [get certificate end date](#get-certificate-end-date)
+- [certs](#certs)
+  - [list all certs](#list-all-certs)
+  - [get cert end date](#get-cert-end-date)
 - [service accounts](#service-accounts)
 - [core-dns](#core-dns)
   - [Services DNS Name](#services-dns-name)
 - [k3s](#k3s)
   - [Install / Setup](#install--setup)
-  - [prune old image](#prune-old-image)
+  - [prune old images](#prune-old-images)
   - [check system logs](#check-system-logs)
   - [Workarounds \& Fixes](#workarounds--fixes)
     - [Failed unmounting var-lib-rancher.mount on reboot](#failed-unmounting-var-lib-ranchermount-on-reboot)
@@ -309,7 +311,15 @@ envsubst < ./secret.yaml | kubectl apply -f -
 
 ```
 
-### get certificate end date
+## certs
+
+### list all certs
+
+```bash
+kubectl get cert -n default
+```
+
+### get cert end date
 
 ``` bash
 kubectl get secret certificate-name-tls -o "jsonpath={.data['tls\.crt']}" | base64 --decode | openssl x509 -enddate -noout
@@ -389,7 +399,7 @@ curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION=v1.33.3+k3s1 INSTALL_K3S_EXEC
  sh -
 ```
 
-### prune old image
+### prune old images
 
 prune old images, execute on kubernetes host node