canonical loop
Canonical tags point at each other in a circle. Found by Canonical tag checker →no hreflang
A multilingual page has no language alternates. Found by Hreflang checker →

SEO glossary

Terms and mini-articles for teams and clients—concise context plus links to authoritative references.

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301 Redirect: Permanent RedirectA 301 is an HTTP response that permanently redirects one URL to another, signalling that the destination should become the preferred location.
302 Redirect: Temporary RedirectA 302 is an HTTP response that temporarily directs a request to another URL while the original URL remains the intended long-term location.
307 Temporary RedirectA temporary HTTP redirect that tells the client to repeat a request at another URL without changing its original method or request body.
308 Redirect: permanent move with method preservationAn HTTP status code that permanently redirects a request while requiring the client to preserve its method and request body at the new URL.
401 UnauthorizedHTTP 401 Unauthorized means valid credentials are required before a server returns the requested resource, so public crawlers cannot access it.
404 Not Found404 Not Found is an HTTP response that says the requested URL has no current resource, so users and crawlers cannot retrieve the expected page.
410 Gone: when a URL is permanently retired410 Gone is an HTTP response status for a known resource intentionally removed from its origin server and unlikely to return at that URL.
503 Service Unavailable503 Service Unavailable is an HTTP response for a temporary inability to serve a request, such as controlled maintenance or short-lived overload.

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Zero-click searchesZero-click searches are search sessions with no click to an external result under the stated measurement; they may include abandonment or query refinement.