diff --git a/README.rst b/README.rst
index c2d3a3b..35a80f2 100644
--- a/README.rst
+++ b/README.rst
@@ -48,6 +48,31 @@
                 fingerprint: dd:fa:e8:68:b1:ea:ea:a0:63:f1:5a:55:48:e1:7e:37
                 fingerprint_hash_type: sha256|md5
 
+* The OpenSSH client configuration with definition of known_hosts using
+public key instead of fingerprint
+
+  - If `purge_defined` is set to `true` it will remove old known_hosts file
+    and start with a fresh one causing that known_host undefined in the pillar
+    will not be included.
+
+  .. code-block:: yaml
+
+      openssh:
+        client:
+          enabled: true
+          user:
+            root:
+              enabled: true
+              purge_undefined: false
+              user:
+                name: 'root'
+                home: '/root'
+              known_hosts:
+              - name: 10.11.1.50
+                port: 22
+                type: ssh-rsa
+                host_public_key: AAA...fkP
+
 * The OpenSSH client configuration with keep alive settings:
 
   .. code-block:: yaml