The issue here is that people are treating reference materials as tutorials intended to cover your exact concern at the moment. You are expected to know what a narg is and what flargling means. In more real terms, the documentation for screen savers https://developer.apple.com/documentation/screensaver?langua... won't explain what a view is, what subclassing is, or what a Rect is. Those are required knowledge to consume the documentation and it's not a documentation failure that this is true.
No, you missed the point. The problem isn't "narg" or "flargling" - those are just random stand-ins for normal words. Instead the problem is that the description says nothing that isn't already said by the symbol name. Whether or now you know what "narg" and "flargling" mean, a documentation page for Nargflargler that just describes it as "Flargles the narg" provides zero additional information to you.