For admission using immigrant visas, check each traveller’s passport, visa validity and the actual post-issuance entry instructions. Carry a sealed package only if one was issued with instructions to keep it closed; some records are transmitted electronically. Confirm any other documents required for the journey rather than treating an interview checklist as a universal border checklist.
Translations and versions, checked against the actual instruction
Documents filed with USCIS in a foreign language need a full certified English translation. Consular requirements can differ, so read the instruction you were sent rather than assuming one English-only rule everywhere. If a notice contradicts the official portal, investigate the conflict instead of repeating it; notices can contain errors.
Provide what the instruction actually asks for, complete, rather than a partial set. A carrier's own boarding requirements are a separate matter from the documents immigration officers examine on arrival, so confirm both sets independently rather than assuming that a boarding pass already issued means every admission document is in order. An airline representative checking in a passenger is applying the carrier's rules, not adjudicating admissibility, and a document accepted at the counter can still be questioned later at the border.
Carry the complete official set identified for the actual stage reached, and keep a copy of the airline's own stated document requirements separately, since the two lists can differ and both apply.