Lab PDF data extraction, handover documentation, imaging governance, WCAG evidence packs. Schema first. No hallucinated cells.
They are structured badly. A Certificate of Analysis has columns; they just have no borders. A vendor data book for an oil and gas handover has a contents list, data sheets, and certificates of conformity that do not share a filename convention. A DICOM governance pack cares about study instance UIDs, retention, and who could export a series — not a pretty gallery. A WCAG conformance evidence pack is a trail: pages tested, criteria (1.4.3 Contrast, 2.4.1 Bypass Blocks), artefacts, residual risk.
Generic “document AI” products optimise for a paragraph summary. That is the wrong artefact. You need rows that survive an audit.
Lock a schema with the people who sign the report. Collect a gold set. Try the cheap parsers; they usually fail on borderless tables — we documented that on SI Report Analyser. Then cluster text positions, dual-parse, and emit exceptions. Humans resolve exceptions. The model, if we use one at all, proposes a mapping; it does not write a concentration.
The same pattern applies to funder data import sheets: the destination columns are the schema. Extraction is successful only if the sheet validates.
See also geotechnical CoA screening and funder impact reporting.