What a list check tells you, and what it does not
A dangerous goods list is usually a column of UN numbers in a spreadsheet: what a site stores, what a carrier accepts, what a customer ships. When a new edition of ADR is adopted, the first question is which of those entries change. The check answers it entry by entry. For each UN number you get the Table A columns that change, with the ADR 2025 value and the ADR 2027 value side by side, the new entries ADR 2027 adds, the entries it deletes, and a plain line for every number whose Table A entry is unchanged — so an unchanged entry is a checked answer, not a gap. Each change names the UNECE document and the PDF page it comes from.
The check reads Table A only. ADR 2027 also amends other chapters — packing, tanks, documentation, training — and those can affect a UN number whose Table A entry is unchanged. It does not tell you how to classify a substance or whether a load complies; that stays with the consignor, the carrier and your Dangerous Goods Safety Adviser. The list is never stored: it travels in the address of the result, so the link you copy opens the same check again, and the CSV gives one row per change for a record.
The regulation itself is published by the United Nations Economic Commission for Europe: the ADR editions and the amendment documents the change list is built from are on the UNECE website, and each citation on a result links to the document it quotes. The change feed covers the data FreightUtils serves rather than the regulation: it says when a dataset here was updated, record by record, so a system that copies FreightUtils data can stay in step without re-reading everything.
Best-effort reference information, not legal advice and not a regulatory authority. Classification and compliance are the consignor's and carrier's legal responsibility. Verify against the ADR text that applies and consult a DGSA where required.