While this is generally true, systems like Rails have so much magic going on that "best practices" are actually closer to being part of a specification. Whether

While this is generally true, systems like Rails have so much magic going on that "best practices" are actually closer to being part of a specification. Whether that's noteworthy enough for a dedicated post, and why it can't just be part of Rails documentation, is a separate question - but there's nothing trivial about this kind of advice.