What are the eight parts of a standard unmodified opinion audit report for a nonpublic entity and what is the main content provided in each part?

1. What are the eight parts of a standard unmodified opinion audit report for a nonpublic entity and what is the main content provided in each part?
2. What are the most significant differences between the AICPA and the PCAOB standard unmodified opinion audit reports?
3. When should the auditor include an explanatory paragraph in an unmodified opinion audit report?