Update on March 2, 2013: Baidu now supports the canonical tag.
Google has introduced the canonical attribute to SEOs and webmasters for a while. And the attribute is very useful as an alternative way to 301 redirection.
But for Baidu, the canonical attribute is still unrecognized.
so what to do with Baidu?
We can use the attribute of rel=”index” to let Baidu know which is our main domain.
What is this?
According to W3C, this attribute “refers to a document providing an index for the current document.”
A friend of mine met the issue that both the www and non www domains are indexed by Baidu. For some technical reason, he was unable to direct one to another, to concentrate the domain weight.
So he tried the canonical attribute first, but as expected, it didn’t work. Both of the two domains were still being ranked. Later I told him to try the rel=”index” attribute instead. I wasn’t so sure either because this attribute is not very common outside WordPress blogs. The good news was, it worked, 🙂
Baidu removed the unnecessarily indexed page and kept only the preferred one.