Evidence quality ladder
Strong
Official records, exact Google listing URLs, issuer credential directories, dated screenshots, domain/business records, direct test results and multiple independent sources that corroborate the same fact.
Useful but needs context
Shared phone numbers, shared websites, similar page templates, review patterns, advertisements and archived pages. These may support a relationship but often need additional verification.
Weak by itself
Rumor, competitor statements, anonymous accusations, assumptions about ownership, or conclusions based only on a company's pricing or ranking.
Every evidence item should record
Source URL · date/time observed · screenshot or saved copy when appropriate · what the source actually shows · what remains uncertain · which listing/company it relates to.
Best practice: Preserve the raw fact first. Write your interpretation separately.