AFAIK, all PA schools throughout the state that are PIAA-affiliated (public, Catholic, charters) are officiated by PIAA-certified referees. There may be independent schools, private or charter, that use IAABO, although I do not know this for a fact. Secondly, IAABO boards may co-exist with PIAA chapters, but I think refs wear PIAA patches, not IAABO, for school games. Lastly, IAABO may assign some rec leagues, but, again, I do not know this for a fact, and all the rec leagues I work and know of use PIAA officials.