Collect identity and family relationship records, a clear description of the specific proposal under consideration, and any open questions about eligibility, funding and the current official instructions, then follow the government's stated next steps for forms and evidence.
Rely on the current official version of the instructions
The official source describes further USCIS instructions being issued after an initial payment step, so confirm the current version before assuming another applicant's checklist applies unchanged. Keep a dated record of which version of the official terms informed any decision made. Current official instructions and the applicant’s identity, history, and payment-source records answer the question; a third-party summary does not.
For documents, create a dated source file for official terms and a separate personal evidence file for identity, family, immigration history, and payment source. The decision is which original record proves each point if later instructions request more than the initial form. Hypothetical example: A geotechnical-consultancy founder funds a gift payment from a business sale; the applicant should preserve sale, tax, and bank records before later instructions request the source trail.