Display messsages to anonymous users but only certain sections

On my site users can submit content.

I want a message to display on the user submitted content that is only visible to anonymous users.
The message should include a link that allows anonymous to register with the site.
The message should only appear on the user generated content and not only any other section of the site.

My site has two types of user generated content, and if possible, I only want the message to appear on the first type.

What is the best way of doing this?