Content types hiding and permission

I'd like to disable/hide some content types site-wide so that only Administrators 开发者_开发知识库can add them. What would be the best practice to do it? Does GenericSetup provide any XML for such a task or do I need to create a custom import step?

Wouldn't this just be a question of assigning the "Add [Content type]" permission to the appropriate role? (Or creating such a permission if your content type assumes use of the general "add content" permission?)