Google now supports
<link rel="canonical">, which allow a page to point to the canonical version of itself. This would help to fix a problem with Stack Overflow's Google search results, in that questions appear multiple times for no good reason.
For example, the result page for:
- "How to find header dependencies for large scale projects on linux"
shows the question three times under different URLs, starting with the canonical one but then also including the superfluous:
If each page had in its
<head> section a
<link rel="canonical"> pointing to the canonical page, that shouldn't happen any more.
(Meta meta: Try as I might I can't get links to work. Apologies for the lack of links in this question.)