Google said the best approach for when you allow others to syndicate and publish your content is to make them use the rel=canonical attribute, so Google knows where the source of the article is.

Google said on Twitter “For syndication, using rel=canonical is the best approach (it doesn’t guarantee only one version is shown though).” Google is saying here it helps but won’t 100% guarantee that only one version of the content will be shown in Google. Google may still show a syndication partner if all the signals are not clear and consistent.

Here is the tweet:

We covered this before when Danny Sullivan from Google went on about this saying make your syndication partners canonical to your content.

Forum discussion at Twitter.