How do I write the heading "Summary of Briefing Report"?

Use a clear, professional heading. Correct the spelling and capitalization like one of these options, depending on formality and layout:

• Summary of Briefing Report
• Summary — Briefing Report
• Briefing Report: Summary
• Executive Summary (if it's the main summary for decision-makers)

Choose title case (capitalize major words) for formal documents, or sentence case ("Summary of briefing report") for a simpler style.