What the documents look like
General trade export declaration generates, for every shipment, four document types: the export customs declaration form, the commercial invoice, the packing list and the contract. In contract-to-transaction-material comparison these carry different roles. The contract records seller and buyer, goods, quantity, amount and trade terms. The commercial invoice and the packing list are execution evidence for the contract terms. The export customs declaration form is the carrier for the customs filing. Compared with general trade import declaration, export declaration also affects export tax refund voucher matching, so whether the parties, amounts and quantities agree across contract, invoice, packing list and declaration form bears directly on document rejection and inspection, declaration error and refund progress. Data sources include China International Trade Single Window, the customs code library, forwarder bills of lading and enterprise ERP. Typical operating parties are trading companies, customs brokers and documentation clerks. Material update frequency is per shipment; this page does not derive batch synchronization or real-time trigger mechanisms from that.
Constraints at the retrieval step
The knowledge base search node can associate one or more knowledge bases that use the same vector model; bases on different vector models cannot be associated together. Retrieval treats the knowledge base as the smallest search unit, and a collection only classifies data for management. Semantic retrieval computes similarity by vector distance, full-text retrieval depends on keyword hits, hybrid retrieval merges the two paths with RRF, and result reranking uses a ReRank model for a second ordering and returns a score from 0 to 1. Minimum relevance takes effect only under semantic retrieval or when result reranking is used, and the reference cap is measured in tokens. Reference content is output as an array whose length can be 0, so the empty-result path still completes. Retrieval results and similarity scores do not constitute a permission, party or authorization judgment, and retrieval itself does not perform approval, database writes or external synchronization.
Hypothetical paper exercise sample: a documentation clerk at a trading company is checking one export contract against one commercial invoice. The contract text reads: "Seller: Huadong Import and Export Co., Ltd.; Buyer: an overseas purchaser; Goods: stainless steel fasteners; Quantity: 1000 pieces; Unit price: USD 2.00; Trade term: FOB Shanghai; Signing date: 10 March 2025." The commercial invoice text reads: "Invoice No.: INV-2025-0310; Seller: Huadong Import and Export Co., Ltd.; Buyer: an overseas purchaser; Goods: stainless steel fasteners; Quantity: 1000 pieces; Unit price: USD 2.00; Trade term: FOB Shanghai." The draft sentence to be judged is: "The contract and the commercial invoice agree on quantity, unit price and trade term, and the parties are the same, so the customs declaration form can be submitted for completion." This draft sentence concerns only field comparison between the contract and the invoice. It does not involve the declaration form or the packing list, and no approval or authorization has been obtained.
Configuration and implementation checks
The table below lists, around the sample above, the documented settings or implementation checks relevant to this page's primary task. The values are starting points for this hypothetical exercise; the reason for each choice and the comparison object are stated together, and they do not represent official default values.
| Configuration item | Hypothetical starting point for this exercise | Reason for the choice and comparison method |
|---|---|---|
| Associated knowledge base | One export contract and transaction material base | First check the vector model identifier used by the base and confirm it matches the search node requirement; bases on different models are not associated together |
| Search mode | Hybrid retrieval | The contract and invoice contain proper nouns such as goods name and trade term and also natural-language clauses; compare recalled entries against semantic retrieval alone and full-text retrieval alone |
| Reference cap | 1500 tokens as the hypothetical starting point | The two sample documents total a few hundred characters; take this value to observe whether complete clauses are truncated; compare reference completeness against the hypothetical values 800 and 2500 |
| Minimum relevance | 0.30 as the hypothetical starting point | First mark paragraphs in the sample that concern quantity and unit price as relevant and other paragraphs as irrelevant, then observe whether the two groups are separated at this threshold; it takes effect only under semantic retrieval or result reranking |
| Question optimization | Enabled | The sample question contains references such as "this contract" and "the above invoice"; compare the original question and the optimized question for whether the party and object were altered |
| Result reranking | Enabled according to the setting | When hybrid retrieval returns many candidates, use the ReRank score for a second ordering and compare the position of relevant paragraphs before and after reranking |
Three common errors
- Treating a retrieval hit as completed authorization or approval. The sample draft sentence states only that contract and invoice fields agree. If it is used to conclude that the declaration form can be submitted for completion, retrieval results are conflated with business authorization. Retrieval does not verify party qualifications and does not perform filing.
- Treating an unstated field as a negation or a conflict. Neither the sample contract nor the sample invoice states the declaration form number or the number of packed pieces. If the draft sentence reads "the missing packing information means the contract is invalid," an unsupported point is written as a negation. Only explicitly mutually exclusive values in the same field constitute a contradiction; an unstated field is pending verification.
- Associating bases on different vector models together. If a contract base and an invoice base that use different vector models are both selected into the search node, the same-vector-model requirement is violated. The correct approach is to check the identifier first, exclude those that do not conform, and record the actual observation without inferring missed recall or redundant results.
How to verify the setup
- Enter the sample contract text and invoice text above, and compare the five fields of party, goods, quantity, unit price and trade term across the two documents. If the five fields match item by item, the draft sentence's claim that quantity, unit price and trade term agree and the parties are the same is supported. If a field is unstated on one side, mark that item as pending verification, not as a negation.
- Enter the sample draft sentence as the retrieval question and compare whether the recalled reference content covers the paragraphs in the contract and invoice that contain quantity, unit price and trade term. If the reference content contains those paragraphs, the sample is retrievable under the current search mode and reference cap. If the reference content is an empty array, record that observation, check whether the data has completed training and whether the question is too short, and do not claim that the rule necessarily returns empty.
- Enter the sample contract text and invoice text and compare whether the draft sentence contains authorization wording such as "the customs declaration form can be submitted for completion." If such wording appears, judge the sentence to exceed the scope of contract-to-invoice comparison and require declaration form and packing list checks plus authorization material. If it does not appear, confirm only the field comparison portion; authorization to complete the declaration form remains unsupported.