A dated copy of the executive order and the official programme page and questions-and-answers, personal eligibility and identity documents, and evidence of the lawful source of the funds to be paid.
Official material, captured on the day
The discipline worth adopting is to capture the official sources at the moment of any decision, with the date recorded. Terms established by executive action can be revised, and an applicant who acted on a particular published description should at least be able to show what it said and when. Alongside that, ordinary personal documentation is needed: identity, immigration and travel history, and anything bearing on admissibility. The lawful source of the money should be documented to the same standard any significant transfer would require, since the question of where funds came from arises in more than one context. What is not documentation is a promoter's brochure or an intermediary's assurance about timing or outcome.
Hypothetical example: Niko, a Canadian architectural technologist, wants to preserve a complete record before considering a Gold Card payment. His first review should save dated official programme pages, payment instructions, receipts, identity records, and civil documents that establish family relationships. The official materials settle the programme description at the time of the decision; a receipt settles that a payment was made, not that every eligibility issue has been resolved. He should keep original electronic files and note the retrieval date. The common error is relying on a screenshot supplied by an intermediary when the official terms have been amended or the payment direction is unclear.