* A fictional entity: The name and concept might be from a book, game, or other work of fiction.
* A private or very small initiative: If it's a real project, it might be so small-scale or localized that it hasn't been documented online.
* A misunderstanding or misspelling: There might be a similar-sounding name or project that's been misremembered.
To find out more, you'd need to provide more context: where did you hear about this "Cl-average Middle School"? Knowing the source might help determine if it's real or fictional.