Which is the attribute to double-click a form in Solution Explorer and open in code view in Visual Studio?

Question

I used to know of a class attribute that you could set your classes as "form" or as "code" and if you set a form as "code", double clicking it's file in the Solution Explorer, would open the form in code view instead of the default form view.

I can't remember what's that attribute called, anyone knows?

Answer 1

Nevermind, found it:

[System.ComponentModel.DesignerCategory("code")]