All high school sports rules are administered by the National Federation of High Schools (NFHS). There are important differences between the rules for club, scholastic, and collegiate soccer. Each year, NISOA publishes a document called “Comparative Study of Rules and Laws,” which compares these rules.
FHSAA makes a few significant modifications to the NFHS rules, which you must know to pass the online exam. These modifications are detailed in the “FHSAA Soccer Sport Manual.”
Both documents can be found on the Downloads page.