Sources and references

This page explains what we treat as a source and how sources are handled in our writing.

Source hierarchy

• Primary technical sources — published standards, specification sheets, and formal documentation.
• Direct testing — our own measurements and observations, described with their method and limits.
• Established reference works — textbooks and technical references in the relevant field.
• Secondary reporting — used for context only, and identified as secondary.

What we do not treat as sources

Retailer product copy, manufacturer marketing claims that cannot be verified, forum consensus, and unattributed figures circulating online are not sources. Where a widely-repeated figure has no traceable origin, we say that rather than repeating it.

Citation

Where a specific standard or document underpins a claim, we name it in the text so readers can verify it independently. We do not cite sources we have not consulted directly.