Check this out http://laravel.com/docs/5.0/validation#custom-validation-rules

Thank you, I already read the documentation, but I do not understand how to procede.

I would like to use my rules in several places of my application, so I suppose that I have to use a Validator class.

Where should I create it? Should I create it inside the "Services" folder?

Then I'm said to register that class with the code

    Validator::resolver(function($translator, $data, $rules, $messages)
    {
        return new CustomValidator($translator, $data, $rules, $messages); 
    });

Where should I put that code? In which class? In which function?

Thank you, I've finally have it working.