Source hierarchy
- 1
Legislation, government departments, regulators and official standards bodies.
- 2
Original technical specifications, manufacturer documentation and controlled project evidence.
- 3
Recognised industry organisations and peer-reviewed or primary research.
- 4
Commercial technical material used only where the claim is clearly attributed and no stronger source is available.
Regulated and safety-led topics
Official guidance is linked visibly on pages concerning PUWER, DSEAR, packaged goods, EPR, DRS, PPWR, barcodes, machine guarding and operational-technology security. Readers should recheck the current source before acting.
What is not treated as evidence
A search snippet, marketplace listing, anonymous forum post, generic stock image, unverified performance claim or automatically generated summary is not sufficient evidence for a technical or legal conclusion.
Quotes and statistics
Long copied passages are avoided. Statistics should identify the source, period, scope and units. Where no reliable current figure is available, the page should explain the information to collect instead of inventing a benchmark.
Links and availability
External sources can move or be updated. A broken link does not make the underlying topic disappear; it should trigger a source review and replacement with the current official page.