A canonical tag tells search systems which page a publisher prefers, but it does not independently prove ownership or authenticity.
Read the browser address first
Capture the complete final hostname after any redirect and distinguish it from text displayed inside the page.
A familiar label can point to a different destination than the address bar shows.
Inspect the declared canonical
Record whether the canonical is self-referential, points elsewhere or is missing.
Cross-domain canonicals may be intentional, but they need an explanation supported by the publisher and site history.
Compare social and structured URLs
Open Graph, WebSite Schema and breadcrumb URLs should generally align with the preferred canonical origin.
Conflicting origins can indicate stale templates, copied pages or an incomplete migration.
Do not use canonical as ownership proof
Anyone controlling a page can declare a canonical URL.
Treat the tag as publishing intent and verify the relationship through independent source and infrastructure evidence.
Document the mismatch clearly
State which URL was visited, which canonical was declared and when the check occurred.
Keep the Mars Market address claim pending until the discrepancy is resolved.