According to the IIA guidance, engagement supervisors' review notes are used during the audit process to ensure thoroughness and accuracy. Once these review notes have been addressed, they can be removed from the final documentation. This practice ensures that the final audit report is clear and concise, containing only the necessary documentation to support audit findings and conclusions. The review notes are considered part of the working papers during the review process but do not need to be retained in the final audit documentation once all issues have been resolved.
Reference:
The Institute of Internal Auditors (IIA) Standard 2330 - Documenting Information: "Internal auditors must document relevant information to support the conclusions and engagement results." IIA Practice Guide on "Audit Documentation"