I need to get my copy of the Spell Comp. from my supplier.
But regardless, everything published by WotC is considered "Official". Now it might not be core rules but it is "Official". So anything in the book is most definitely "Official".
So stating it is not so in error. Stating it is not "Core Rules" is true. Stating it is not RAW is likewise false since again, everything WotC publishes is considered "Official". Now it could be considered "Optional" or "Variant" rules, that much is subject to interpretation - but it is "Official RAW".
But regardless, everything published by WotC is considered "Official". Now it might not be core rules but it is "Official". So anything in the book is most definitely "Official".
So stating it is not so in error. Stating it is not "Core Rules" is true. Stating it is not RAW is likewise false since again, everything WotC publishes is considered "Official". Now it could be considered "Optional" or "Variant" rules, that much is subject to interpretation - but it is "Official RAW".