Purpose of Tolerance field on both the profile class (table ar.hz_cust_profile_classes) and customer

Our business users would like clarification on the purpose of the 'Tolerance' field on both the profile class (table ar.hz_cust_profile_classes) and customer standard (table ar.hz_customer_profiles).
They are under the assumption that if an order goes in OM that causes the credit exposure to exceed the credit limit + tolerance % that the order will be placed on hold no matter that the score and recommendation in credit management.