Everyone knows what a school is, but the question of what constitutes an individual school is more complex than one would expect. Since not all individual records that appear in state or federal data files are schools, this creates a persistent challenge for educational researchers. In order to ensure that we have an accurate accounting of charter schools, the National Alliance uses a modified count system when we count charter schools. This white paper focuses on charter school campuses and explains why these records are found in datasets as well as when it might be more helpful to exclude these records from analyses.