diff --git a/modules/source/11_training/training_dev.py b/modules/source/11_training/training_dev.py
index f1e3cf92..9471a85b 100644
--- a/modules/source/11_training/training_dev.py
+++ b/modules/source/11_training/training_dev.py
@@ -186,6 +186,8 @@ class MeanSquaredError:
 
 # %% [markdown]
 """
+## 🔧 DEVELOPMENT
+
 ### 🧪 Unit Test: MSE Loss
 
 Let's test our MSE loss implementation with known values.