Response to the following questions:
1. What are the auditor's documentation requirements for an audit of ICFR?
2. What are the types of reports that an auditor can issue for an audit of ICFR? Briefly identify the circumstances justifying each type of report.
3. Under what circumstances would an auditor give an adverse opinion on the effectiveness of an entity's ICFR?
If possible, please give examples to better understand your answers.