This. Unless it's changed in the past few years, each student taking any subject tests will receive a book with all the tests in it. The day of the test, the student can change his/her mind on the actual tests to be taken, the order to be taken, and the number to be taken - if the change results in more tests than the student originally registered, the CB will bill you for the difference. I believe if the number decreases, CB won't refund the difference.