MVC Question: Should I put form validation rules in the controller or model?

Question

On one hand form validation could be seen as part of the application logic and therefore belonging in the model.

On the other hand, it deals directly with the input

Answer 1

I would say the form validation code should be in the controller (not the model) in most cases.

Madmartigan put it best in his comment above "Form validation !== Data validation. Not all forms interact with a model"

Web forms are logically part of the View/Controller part of MVC, since the user interacts with them in the view.