diff --git a/README.md b/README.md
index 5b65be2..7a54034 100644
--- a/README.md
+++ b/README.md
@@ -209,6 +209,97 @@ Then run it:
 ansible-playbook -i hosts ./your-playbook.yml
 ```
 
+### Installing X-Pack Features
+
+X-Pack features, such as Shield, are supported for Elasticsearch 2.4 only. This feature is currently experimental.  To enable X-Pack set the parameter `es_enable_xpack` to true and list the required features in the parameter `es_xpack_features`.  The following additional parameters allow X-Pack to be configured:
+
+* ```es_message_auth_file``` System Key field to allow message authentication. This file should be placed in the 'files' directory.
+* ```es_role_mapping``` Role mappings file declared as yml as described [here](https://www.elastic.co/guide/en/shield/current/mapping-roles.html)
+
+```
+es_role_mapping:
+  power_user:
+    - "cn=admins,dc=example,dc=com"
+  user:
+    - "cn=users,dc=example,dc=com"
+    - "cn=admins,dc=example,dc=com"
+```
+
+* ```es_users``` - Users can be declared here as yml. Two sub keys 'native' and 'file' determine the realm under which realm the user is created.  Beneath each of these keys users should be declared as yml entries. e.g.
+
+```
+es_users:
+  native:
+    kibana4_server:
+      password: changeMe
+      roles:
+        - kibana4_server
+  file:
+    es_admin:
+      password: changeMe
+      roles:
+        - admin
+    testUser:
+      password: changeMeAlso!
+      roles:
+        - power_user
+        - user
+```
+            
+            
+* ```es_roles``` - Elasticsearch roles can be declared here as yml. Two sub keys 'native' and 'file' determine how the role is created i.e. either through a file or http(native) call.  Beneath each key list the roles with appropriate permissions, using the file based format described [here] (https://www.elastic.co/guide/en/shield/current/_file_based_roles.html) e.g.
+
+```
+es_roles:
+  file:
+    admin:
+      cluster:
+        - all
+      indices:
+        - names: '*'
+          privileges:
+            - all
+    power_user:
+      cluster:
+        - monitor
+      indices:
+        - names: '*'
+          privileges:
+            - all
+    user:
+      indices:
+        - names: '*'
+          privileges:
+            - read
+    kibana4_server:
+      cluster:
+          - monitor
+      indices:
+        - names: '.kibana'
+          privileges:
+            - all
+  native:
+    logstash:
+      cluster:
+        - manage_index_templates
+      indices:
+        - names: 'logstash-*'
+          privileges:
+            - write
+            - delete
+            - create_index
+```                
+                
+* ```es_xpack_license``` - X-Pack license.  The license should be declared as a json blob.  Alternative use Ansible vault or copy the license to the target machine as part of a playbook and access via a lookup e.g.
+
+```
+es_xpack_license: "{{ lookup('file', '/tmp/license.json')  }}"
+``` 
+
+For a full example see [here](https://github.com/elastic/ansible-elasticsearch/blob/master/test/integration/xpack.yml)
+
+
+
 ### Additional Configuration
 
 Additional parameters to es_config allow the customization of the Java and Elasticsearch versions, in addition to role behaviour. Options include:
@@ -219,6 +310,8 @@ Following variables affect the versions installed:
 * ```es_version``` (e.g. "2.4.2").  
 * ```es_api_host``` The host name used for actions requiring HTTP e.g. installing templates. Defaults to "localhost".
 * ```es_api_port``` The port used for actions requiring HTTP e.g. installing templates. Defaults to 9200.
+* ```es_api_basic_auth_username``` The Elasticsearch username for making admin changing actions. Used if Shield is enabled. Ensure this user is admin.
+* ```es_api_basic_auth_password``` The password associated with the user declared in `es_api_basic_auth_username`
 * ```es_start_service``` (true (default) or false)
 * ```es_plugins_reinstall``` (true or false (default) )
 * ```es_plugins``` an array of plugin definitions e.g.:
@@ -239,7 +332,7 @@ es_java_opts:
 Earlier examples illustrate the installation of plugins for 2.x.  The correct use of this parameter varies depending on the version of Elasticsearch being installed:
  
  - 2.x. - For officially supported plugins no version or source delimiter is required. The plugin script will determine the appropriate plugin version based on the target Elasticsearch version.  
- For community based plugins include the full path e.g. "lmenezes/elasticsearch-kopf" and the appropriate version for the target version of Elasticsearch.
+ For community based plugins include the full path e.g. "lmenezes/elasticsearch-kopf" and the appropriate version for the target version of Elasticsearch.  This approach should NOT be used for X-Pack related plugins e.g. Shield.  See X-Pack below for details here.
  
 If installing Marvel or Watcher, ensure the license plugin is also specified.  Shield configuration is currently not supported but planned for later versions.