Preferred sources
Government agencies, regulators, official manufacturer and platform documentation, original standards, recognized institutions, academic literature where relevant, and direct program documentation are preferred.
Secondary sources
High-quality secondary sources can add context or practical perspective, but they should not replace an available primary source for a central factual claim.
Commercial sources
A vendor may be the best source for how its own product works, pricing, warranty, or feature limitations. We identify vendor-specific information as such rather than treating it as independent evidence.
Community sources
Forums and community discussions may help identify common experiences or questions, but user-generated claims require verification before being presented as fact.
Links
We link to the most specific useful source page available. A source link is not an endorsement of every view or product on that site.
Freshness
Sources for changing material are reviewed for publication/update date, current applicability, redirects, and superseding guidance.
Source conflicts
When authoritative sources disagree or rules vary by jurisdiction or provider, we state the limitation rather than inventing a universal answer.