HARRISBURG, Pa. - Some Pennsylvania physicians are offering stock doctor's notes for use by parents wishing to have their children exempted from wearing masks in school, according to state health officials who say they have referred the matter for possible disciplinary action.A statewide, universal mask mandate for Pennsylvania schools went into effect Tuesday as the Wolf administration seeks to keep school buildings open for in-person learning amid the latest surge in COVID-19 cases, hospitalizations and deaths.The acting health secretary's face covering order contains an exemption for students for whom wearing a mask would cause or worsen a medical condition.