That's my point. Things like ISBN, RFC, etc. are magic words. Things like __NOTOC__ and {{PAGENAME}} are no more magic than [[Link]], and so shouldn't be described as such.
The thing that makes them magic words is that they are *words* (or, at least, acronyms). "[[" is just punctuation. Even though they require particular punctuation to work, they are still words that have some extra purpose beyond just being text - we call that "magic".