Flying through Korea: which travel documents should passengers confirm with the carrier?

Kapy's editorial team reconstructed this discussion from a recurring Chinese or Vietnamese community need about a flight through Korea. It is not a repost, does not represent a collected user, and contains no copied comments or personal data. If you handled a similar case recently, share only the official channel checked, the year, the location, and the order of preparation. Do not present an individual experience as a promise for another person. Never post passport or residence-card numbers, application IDs, addresses, account details, verification codes, or document images. Requirements can differ by facts, place, and time, so readers should confirm the current position with the responsible institution before acting.