It is actually a well written document with a table of contents, chapter summaries, checklist, flowcharts and examples.
About 30 minutes to get a good grasp.
Or corporation or entity registered with Sec. Of State (page 2) unless exceptions are met (page 4).
One takeaway is the filing deadlines:
"If your company already exists as of January 1, 2024, it must file its initial BOI report by January 1, 2025. If your company is created or registered to do business in the United States on or after January 1, 2024, and before January 1, 2025,..."