Rel Canonical

I asked this before and did not get a straight answer.

Do all the WEB 2.0 platforms have a rel canonical function already built in? Since posts show up on the homepage and have a separate page, this could be considered as duplicate content. Has anyone had any problems?

Cheers!

I'm not sure about a direct answer to your main question, but as to your "does it become duplicate content" question, I believe the answer is no or else people wouldn't be utilizing web 2.0s to the extent that they do without manually adding canonical tags.