1 Introduction  
2 Block-Oriented Nonlinear Models: Structures, Representation and Noise Framework  
3 Bussgang’s Theorem and Separable Processes  
4 Linear Approximations of Nonlinear Systems  
5 Cost Function  
6 Initialization Methods: an Overview  
7 Single Branch Models  
8 Parallel Branch Model Structures  
9 Feedback Model Structures  
10 Pros and Cons of the Model Structures  
11 Guidelines for the User  
13 Future Research Directions  
14 Conclusion  