Answer:Summary
Explanation: Summary is the briefing of any information or data and reducing the details about the subject.It is not a part of the report while it is designed because detailing is the part where the description is mentioned with every element so the requirement for summary is in that part and not in the report.
Other option are the part of the report designing because group footer is used for presenting the summaries of group, page footer the area below the main text and detail is the description of every element of the subject.Thus the only exception in the designing of report is summary.