Update README.md

README.md

@@ -128,6 +128,14 @@ Schema = GraphQL::Schema.define do
 end
 </pre>
 
+When using a policy object, you may want to allow [introspection queries](http://graphql.org/learn/introspection/) to skip authorization. A simple way to avoid having to whitelist every introspection type in the `RULES` hash of your policy object is to check the `type` parameter in the `guard` method:
+
+<pre>
+def self.guard(type, field)
+  <b>type.introspection?</b> || RULES.dig(type, field)
+end
+</pre>
+
 ## Priority order
 
 `GraphQL::Guard` will use the policy in the following order of priority: