Cross Domain Duplicate Content

[mattys]

Hi

My client has a series of websies, one main website and several mini websites, articles are created and published daily and weekly, one will go on a the main website and the others on one, two, or three of the mini sites.

To combat duplication, i only ever allow one article to be indexed (apply noindex to articles that i don't wanted indexed by google, so, if 3 sites have same article, 2 sites will have noindex tag added to head).

I am not completely sure if this is ok, and whether there are any negative affects, apart from the articles tagged as noindex not being indexed. Are there any obvious issues?

I am aware of the canonical link rel tag, and know that this can be used on the same domain, but can it be used cross domain, in place of the noindex tag?

If so, is it exactly the same in structure as the 'same domain' canonical link rel tag?

Thanks

Matt

[AdamThompson]

Yes, the canonical tag will work across domains: http://searchengineland.com/google-supports-cross-domain-canonical-tag-32044

[mattys]

Thanks Adam

Is there a problem with using noindex as noted in my original post?

Having read a bit about canonical now and watched matt cutts video, the advice is to use other forms of redirect, e.g. 301, first, 'rel=”canonical” link element is seen as a hint and not an absolute directive' However, is not feasible that client can manually upload an ediited .htacess file with new 301 redirect each time and article is uploaed, acorss different domains.

So, what i am trying to say is, what would be the best method in my situation?

Matt