diff --git a/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/CSV.java b/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/CSV.java
new file mode 100644
index 0000000..9781cf4
--- /dev/null
+++ b/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/CSV.java
@@ -0,0 +1,11 @@
+package com.reflectoring;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface CSV {
+}
\ No newline at end of file
diff --git a/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/TestMarkerAnnotation.java b/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/TestMarkerAnnotation.java
new file mode 100644
index 0000000..01f9bc5
--- /dev/null
+++ b/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/TestMarkerAnnotation.java
@@ -0,0 +1,16 @@
+package com.reflectoring;
+
+public class TestMarkerAnnotation {
+
+    public static void main(String[] args) {
+
+        XYZClient client = new XYZClient();
+        Class clientClass = client.getClass();
+
+        if (clientClass.isAnnotationPresent(CSV.class)){
+            System.out.println("Write client data to CSV.");
+        } else {
+            System.out.println("Write client data to Excel file.");
+        }
+    }
+}
diff --git a/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/XYZClient.java b/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/XYZClient.java
new file mode 100644
index 0000000..a84d07c
--- /dev/null
+++ b/core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/XYZClient.java
@@ -0,0 +1,6 @@
+package com.reflectoring;
+
+@CSV
+public class XYZClient {
+
+}
\ No newline at end of file