diff --git a/docs/class4/module2/lab1/lab1.rst b/docs/class4/module2/lab1/lab1.rst
index 126a8fe..c30b577 100644
--- a/docs/class4/module2/lab1/lab1.rst
+++ b/docs/class4/module2/lab1/lab1.rst
@@ -1,10 +1,62 @@
-Enable API discovery
-====================
+Enable API Validation
+=====================
 
-Enable Endpoint Discovery
--------------------------
+In the previous section, we enabled AOU Protection. API Protection is based on rules (allow, deny), but API Validation goes deeper into the validation.
 
+API Validation validates the requests and the responses, but also the content (JSON payload) based on the OpenAPI Specifications.
 
-Enable PII Discovery
---------------------
+As a reminder, this is the difference between Protection and API Validation. 
+
+.. image:: ../pictures/slide-api-protection.png
+   :align: center
+   :scale: 40%
+
+.. note:: As an example, API Validation validates if the value of a JSON key matches the specifications (integer, string, array ...)
+
+Example below
+
+.. code-block:: YAML
+   :emphasize-lines: 24, 36, 38
+
+    /adjectives:
+    get:
+      description: List all adjectives
+      tags:
+        - adjectives
+      responses:
+        '200':
+          description: a list of adjectives with their index
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Adjectives"
+    post:
+      description: create an adjective
+      tags:
+        - adjectives
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                name:
+                  type: string
+            example:
+              name: worried
+      responses:
+        '201':
+          description: adjective created
+          content:
+            application/json:
+              schema:
+                type: object
+                properties: 
+                  id:
+                    type: integer
+                  name:
+                    type: string
+              example:
+                id: 4
+                name: worried
 
diff --git a/docs/class4/module2/lab2/lab2.rst b/docs/class4/module2/lab2/lab2.rst
index 95e141c..126a8fe 100644
--- a/docs/class4/module2/lab2/lab2.rst
+++ b/docs/class4/module2/lab2/lab2.rst
@@ -1,18 +1,10 @@
-API Discovery outcomes
-======================
+Enable API discovery
+====================
 
-Endpoint Discovery
-------------------
+Enable Endpoint Discovery
+-------------------------
 
 
-PII Discovery
--------------
+Enable PII Discovery
+--------------------
 
-
-
-Authentication Discovery
-------------------------
-
-
-AI/ML Security Posture
-----------------------
\ No newline at end of file
diff --git a/docs/class4/module2/lab3/lab3.rst b/docs/class4/module2/lab3/lab3.rst
new file mode 100644
index 0000000..95e141c
--- /dev/null
+++ b/docs/class4/module2/lab3/lab3.rst
@@ -0,0 +1,18 @@
+API Discovery outcomes
+======================
+
+Endpoint Discovery
+------------------
+
+
+PII Discovery
+-------------
+
+
+
+Authentication Discovery
+------------------------
+
+
+AI/ML Security Posture
+----------------------
\ No newline at end of file
diff --git a/docs/class4/module2/module2.rst b/docs/class4/module2/module2.rst
index 2bc3786..13c5e25 100644
--- a/docs/class4/module2/module2.rst
+++ b/docs/class4/module2/module2.rst
@@ -1,7 +1,7 @@
 Dynamic API Protection
 ######################
 
-In this section, we will protect the same modern application with F5 Distributed Cloud, but we will enable the **dynamic** protection where SecOps apply the API Discovery and validation.
+In this section, we will protect the same modern application with F5 Distributed Cloud, but we will enable the **dynamic** protection where SecOps apply the API Discovery and Validation.
 
 
 **Module 2 - All sections**
diff --git a/docs/class4/module2/pictures/slide-api-protection.png b/docs/class4/module2/pictures/slide-api-protection.png
new file mode 100644
index 0000000..b851124
Binary files /dev/null and b/docs/class4/module2/pictures/slide-api-protection.png differ