What the documents look like
Letter-of-credit document examination serves the bank's payment conditions, and the central test is documentary consistency. The working materials for one transaction are the letter of credit, the commercial invoice, the bill of lading, the insurance policy, and the draft. Their sources include the issuing bank's advice, UCP600 clauses, the freight forwarder's bill of lading, and the bank's document presentation records. This combination means that citation tracing has to return to the text of each individual document. Any conclusion in an answer must point back to a specific material and field. Materials update per transaction, and the same shipment can produce several versions across different handling stages, so checking uses the currently effective version.
For after-sales questions about a presentation, the practical consequence is that the answer chain is only as strong as the citation behind it. A question about a discrepancy, a presentation deadline, or a document version cannot be answered from a general description of the transaction. It has to be answered from the named document, the named field, and the effective version at the moment of the question.
Constraints at the citation tracing step
The knowledge base search node outputs reference content as an array, and its length may be zero. When no content is retrieved, that output path still completes. The citation upper limit is measured in tokens. The minimum relevance value applies only under semantic retrieval or when result re-ranking is used, and it is a filtering threshold; it does not carry out permission isolation or entity isolation. Knowledge bases selected together must use the same vector model, and bases with different vector models cannot be associated together. Checking therefore begins by comparing identifiers and excluding those that do not match. Whether a retrieved result is adopted still requires human review against the effective version.
Hypothetical paper exercise sample, provided for checking purposes only. Material A states: "Issuing bank advice number LC-2024-0417, advice date 17 April 2024, letter-of-credit amount USD 80,000, latest shipment date 20 May 2024, presentation period 21 days after shipment." Material B states: "Bill of lading number BL-0417A, loaded on board 18 May 2024, port of loading Shanghai, port of discharge Hamburg." The draft sentence to be judged is: "The presentation deadline for this transaction is 10 June 2024." That sentence does not match the starting point stated in the source, because the source states a presentation period counted from the shipment date and does not state a fixed calendar deadline. The sentence is unsupported and must be checked against the letter-of-credit text.
Configuration and implementation checks
| Configuration or check item | Value or action on this page | Explanation |
|---|---|---|
| Associated knowledge bases | Select the letter of credit, invoice, bill of lading, insurance policy, and draft materials | They must use the same vector model; bases with different vector models are not associated together |
| Search mode | Use full-text or hybrid retrieval for number and date fields | Hybrid retrieval merges multiple result paths through RRF |
| Citation upper limit | For this hypothetical exercise, start at 2000 tokens | Chosen to hold several document fragments; compare against a smaller value to observe truncation |
| Minimum relevance | For this hypothetical exercise, start at 0.3 | Compare against a higher threshold to observe how the candidate count changes |
| Result re-ranking | Enable when candidates are many and a re-ranking model is available | The re-ranking score runs from 0 to 1 and can be used for filtering |
| Citation output handoff | Pass the reference array to the answering step | Check each answer statement against the cited source text |
Three common errors
- Treating a retrieval hit as completed authorization. Retrieval returns reference content only. Business approval, database writes, and external synchronization each need their own downstream implementation. A pending review state does not show that operational permission has been granted.
- Treating minimum relevance as a permission or entity filter. That value is a filtering threshold. It does not exclude unrelated business records or unauthorized records, and knowledge bases with different vector models cannot be associated together.
- Accepting the date in the draft sentence at face value. In the sample, the draft sentence states 10 June 2024, while the source states only a presentation period of 21 days after shipment. The two use different starting points, so the comparison must hold the same subject, the same period, and the same field.
How to verify the setup
- Enter the letter-of-credit source text and the bill-of-lading source text from the sample. Compare the date in the draft sentence against the presentation-period starting point stated in the source. When the draft sentence and the source do not agree, mark it unsupported and record the evidence gap. A missing statement or a statement covering only a related stage is recorded as unsupported or pending verification, not as a contradiction.
- Enter a draft sentence that falls outside the material scope, and compare whether the reference array is empty. When the array is empty, the downstream path still completes. Do not conclude from this that a retrieval rule necessarily returns an empty array.
- Enter the sample source text together with a request supported only by evidence from a related stage. Compare whether the subject, the period, and the field are the same. When only related-stage evidence exists, mark the item pending verification. Do not write it as a denial or as a conflict.
Across all three checks, the comparison must use the same subject, the same period, and the same field. A contradiction exists only when the same field carries clearly mutually exclusive values. A pending review does not show that operational permission is absent. Signing, reaching cooperation, and contract effectiveness are three separate facts. A quotation validity period does not state a supply period. Do not add authorization or effectiveness clauses to obtain a definite answer; keep the evidence gap open. The materials needed for a check must sit inside a searchable scope to which there is access, or inside a clearly defined manual input. When they are missing, record the gap.