diff --git a/marker/etc/MarkerDiagram.png b/marker/etc/MarkerDiagram.png
new file mode 100644
index 000000000..6ed4f9c56
Binary files /dev/null and b/marker/etc/MarkerDiagram.png differ
diff --git a/marker/etc/MarkerDiagram.ucls b/marker/etc/MarkerDiagram.ucls
new file mode 100644
index 000000000..0f8376e40
--- /dev/null
+++ b/marker/etc/MarkerDiagram.ucls
@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<class-diagram version="1.2.0" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
+  realizations="true" associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
+  <class id="1" language="java" name="Guard" project="marker" file="/marker/src/main/java/Guard.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="416" y="348"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <interface id="2" language="java" name="Permission" project="marker" file="/marker/src/main/java/Permission.java" 
+    binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="261" y="175"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="3" language="java" name="Thief" project="marker" file="/marker/src/main/java/Thief.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="236" y="355"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <realization id="4">    
+    <end type="SOURCE" refId="1"/>    
+    <end type="TARGET" refId="2"/>  
+  </realization>  
+  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+    sort-features="false" accessors="true" visibility="true">    
+    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
+    <operations public="true" package="true" protected="true" private="true" static="true"/>  
+  </classifier-display>  
+  <association-display labels="true" multiplicity="true"/>
+</class-diagram>
\ No newline at end of file
diff --git a/marker/pom.xml b/marker/pom.xml
index 99dca27a3..74969d2eb 100644
--- a/marker/pom.xml
+++ b/marker/pom.xml
@@ -10,6 +10,21 @@
     <modelVersion>4.0.0</modelVersion>
 
     <artifactId>marker</artifactId>
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>RELEASE</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
+    </dependencies>
 
 
 </project>
\ No newline at end of file
diff --git a/marker/src/main/java/App.java b/marker/src/main/java/App.java
index ca8c036f7..10ec017df 100644
--- a/marker/src/main/java/App.java
+++ b/marker/src/main/java/App.java
@@ -1,12 +1,43 @@
 /**
  * Created by Alexis on 28-Apr-17.
+ * With Marker interface idea is to make empty interface and extend it.
+ * Basically it is just to identify the special objects from normal objects.
+ * Like in case of serialization , objects that need to be serialized must implement serializable interface
+ * (it is empty interface) and down the line writeObject() method must be checking
+ * if it is a instance of serializable or not.
+ * <p>
+ * Marker interface vs annotation
+ * Marker interfaces and marker annotations both have their uses,
+ * neither of them is obsolete or always better then the other one.
+ * If you want to define a type that does not have any new methods associated with it,
+ * a marker interface is the way to go.
+ * If you want to mark program elements other than classes and interfaces,
+ * to allow for the possibility of adding more information to the marker in the future,
+ * or to fit the marker into a framework that already makes heavy use of annotation types,
+ * then a marker annotation is the correct choice
  */
 public class App {
+
+  /**
+   * Program entry point
+   *
+   * @param args command line args
+   */
   public static void main(String[] args) {
+
     Guard guard = new Guard();
+    Thief thief = new Thief();
 
     if (guard instanceof Permission) {
       guard.enter();
+    } else {
+      System.out.println("You have no permission to enter, please leave this area");
+    }
+
+    if (thief instanceof Permission) {
+      thief.steal();
+    } else {
+      thief.doNothing();
     }
   }
 }
diff --git a/marker/src/main/java/Thief.java b/marker/src/main/java/Thief.java
new file mode 100644
index 000000000..33eac5aca
--- /dev/null
+++ b/marker/src/main/java/Thief.java
@@ -0,0 +1,12 @@
+/**
+ * Created by Alexis on 02-May-17.
+ */
+public class Thief {
+  protected static void steal() {
+    System.out.println("Steal valuable items");
+  }
+
+  protected static void doNothing() {
+    System.out.println("Pretend nothing happened and just leave");
+  }
+}
diff --git a/marker/src/test/java/AppTest.java b/marker/src/test/java/AppTest.java
new file mode 100644
index 000000000..615a3c910
--- /dev/null
+++ b/marker/src/test/java/AppTest.java
@@ -0,0 +1,17 @@
+/**
+ * Created by Alexis on 01-May-17.
+ */
+
+import org.junit.Test;
+
+/**
+ * Application test
+ */
+public class AppTest {
+
+  @Test
+  public void test() {
+    String[] args = {};
+    App.main(args);
+  }
+}
diff --git a/marker/src/test/java/GuardTest.java b/marker/src/test/java/GuardTest.java
new file mode 100644
index 000000000..459447367
--- /dev/null
+++ b/marker/src/test/java/GuardTest.java
@@ -0,0 +1,16 @@
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Created by Alexis on 02-May-17.
+ */
+public class GuardTest {
+
+  @Test
+  public void testGuard() {
+    Guard guard = new Guard();
+    assertThat(guard, instanceOf(Permission.class));
+  }
+}
diff --git a/marker/src/test/java/ThiefTest.java b/marker/src/test/java/ThiefTest.java
new file mode 100644
index 000000000..37409ecb3
--- /dev/null
+++ b/marker/src/test/java/ThiefTest.java
@@ -0,0 +1,15 @@
+/**
+ * Created by Alexis on 02-May-17.
+ */
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
+
+public class ThiefTest {
+  @Test
+  public void testGuard() {
+    Thief thief = new Thief();
+    assertFalse(thief instanceof Permission);
+  }
+}