1. The goods arrived, but the documents didn't arrive: this may indeed happen. The appearance of electronic bill of lading has alleviated this problem to some extent.

2. Why not use forward? Because immediate demand is paid by documents, that is, you have to pay before the goods arrive. Disadvantages are: (1) low security; (2) Occupy the buyer's funds, which is not conducive to the liquidity of assets. (Is it equivalent to paying in advance?

Let me add: I guess the true meaning of the sentence "goods arrive first, documents do not arrive" The title means that the goods have arrived, but haven't the documents expired? In this case, the buyer has two options:

1. Pay in advance and get the certificate.

2. Issue a trust receipt to the collecting bank, provide mortgage or guarantee when necessary, lend the documents to the bank to pick up the goods, and then pay after the maturity. Trust receipt is a written document that the buyer, as the trustee of the bank, promises to keep and handle the goods on behalf of the bank, and acknowledges that the ownership of the goods belongs to the bank and the sales proceeds also belong to the bank. In this case, the collecting bank must be responsible to the seller whether the buyer can pay the bill when it expires.