What it means
The annotations can be supplied in HTML, HTTP headers or a sitemap. Each version should list itself and the relevant equivalents, with reciprocal references and complete URLs. Language and optional region codes describe the intended audience. An x-default reference is suitable for a genuine fallback or selection page.
How this affects everyday use
Failures often involve broken URLs, wrong codes, missing return references or links to unrelated homepages. A language selector that changes only a cookie does not create separately crawlable translated pages.
A practical example
An English guide and its German, Dutch and Spanish versions use four stable addresses. Each page lists that same translation group, while each retains its own canonical address.
What to check
- Check every referenced URL, language code and HTTP response.
- Confirm that references return from each equivalent page.
- Compare main content, page language and canonicals across the group.
Practical next steps
- Generate annotations from the actual linked translation records.
- Correct broken references and remove unrelated or missing alternatives.
- Choose one maintained annotation method and validate its output.
Keeping it reliable
Recheck the group when moving a page or adding a language. Keep translations complete and reviewed before making them indexable. Hreflang does not guarantee a ranking gain or automatically translate anything; useful content and accessible pages remain necessary.