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Protecting your site with Gruyere

Friday, June 17, 2011

Based on your feedback, we’re happy to announce that Google web search now supports
link rel="canonical" relationships
specified in HTTP headers as per the syntax described in
section 5 of IETF RFC 5988.
Webmasters can use rel="canonical" HTTP headers to signal the canonical URL for both
HTML documents and other types of content such as PDF files.

To see the rel="canonical" HTTP header in action, let’s look at the scenario of a
website offering a white paper both as an HTML page and as a downloadable PDF alternative, under
these two URLs:

  • https://www.example.com/white-paper.html
  • https://www.example.com/white-paper.pdf

In this case, the webmaster can signal to Google that the canonical URL for the PDF download is
the HTML document by using a rel="canonical" HTTP header when the PDF file is
requested; for example:

Another common situation in which rel="canonical" HTTP headers may help is when a
website serves the same file from multiple URLs (for example when using a content distribution
network) and the webmaster wishes to signal to Google the preferred URL.

We currently support these link header elements for web search only. As we see how webmasters are
using these elements, we’re hoping to add support for them in our other properties. For more
information, please see our Help Center articles about
canonicalization and the
rel="canonical" element.
If you have any questions, please ask in our
Webmaster Help Forum.

Alien Road

So setzen wir das um

We archive Search Central announcements because client questions often trace back to a change that was announced years ago. Reading the original is faster than reconstructing it from second-hand summaries.

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