What is the definition of an outbreak in pre-K-12 schools?

CDC recommends that all states define school-associated outbreaks according to the standards established by the Council of State and Territorial Epidemiologists (CSTE): (A) “multiple cases comprising at least 10% of students, teachers, or staff within a specified core group” (e.g., extracurricular activity, cohort group, classroom, before/after school care, etc.) or (B) “at least three cases within a specified core group meeting criteria for a probable or confirmed school-associated COVID-19 case (laboratory-positive by PCR or antigen testing) with symptom onset or positive test within 14 calendar days of each other; who were not identified as close contacts of each other in another setting outside of the school setting (i.e., household); and that are epidemiologically linked in the school setting or a school-sanctioned activity.”