diff --git a/docs/MO_DG/prepare_model/customize_model_optimizer/Customize_Model_Optimizer.md b/docs/MO_DG/prepare_model/customize_model_optimizer/Customize_Model_Optimizer.md
index 7eb1b79c68e..887860524eb 100644
--- a/docs/MO_DG/prepare_model/customize_model_optimizer/Customize_Model_Optimizer.md
+++ b/docs/MO_DG/prepare_model/customize_model_optimizer/Customize_Model_Optimizer.md
@@ -10,6 +10,11 @@
 
 @endsphinxdirective
 
+
+This article describes Model Optimizer internals. Altering them may result in application instability, and in case of future changes to the API, lack of backward compatibility.
+
+> **NOTE**: If you want to add support for ONNX or PaddlePaddle operations, or you are not familiar with other extension alternatives in OpenVINO, read [this guide](../../../Extensibility_UG/Intro.md) instead.
+
 <a name="model-optimizer-extensibility"></a>Model Optimizer extensibility mechanism enables support of new operations and custom transformations to generate the optimized intermediate representation (IR) as described in the
 [Deep Learning Network Intermediate Representation and Operation Sets in OpenVINO™](../../IR_and_opsets.md). This
 mechanism is a core part of Model Optimizer, as a huge set of examples showing how to add custom logic to support your model.