I have a site for a client. He has content he has written on a page and it looks great. He now wants some of this content on another page, under another heading that contains a collection of his writings. In my understanding this would be duplicate content for the block that is copied. I could block the first page but it is built specifically for that piece of writing. The page with the collection of writings also contains unique writings so I do not want to block that page. Is there anyway to tell Google: Ignore this div of content but use the rest? What is the best route here?I am thinking of explaining to my client the situation of duplicate content and not adding it unless I can do it without any SEO penalties. 
Duplicate content on a site
seo;duplicate content
Is there anyway to tell Google: Ignore this div of content but use the rest?As covered in a post here, there are two potential ways get Google to ignore part of a page included in other pages:JavaScript   Google tends to ignore most JavaScript. That means you  could load up the content you want hidden/ignored/discounted in JS.  The problem is - Google may still understand it/read it/reference  it. The only really safe way is to include the content in an external  JS file, and block that file in robots.txt. (Alternatively - you could  use the x-ref header of NoIndex for .JS files etc.) Otherwise - if you  have the JS in your file, as inline/embedded content - it may still be  used (unlikely, but possible).Frames   You could place the content you want hidden/ignored/discounted  in a separate file. You set the robot-meta for that file as NoIndex  (or you could block it with robots.txt or use the x-ref header of  NoIndex). You then load that content into your page using a Frame.  Google will crawl your page, see the frame, look to the framed file -  see it is blocked (noindex/disallowed), and not touch it.Since the date of this post, Google has become better at crawling and understanding JavaScript, so this statement may not be quite as accurate now:  Google tends to ignore most JavaScript. Of the two choices, I would suggest using an iFrame to a separate source file containing the duplicate content, and then block this source file from being indexed as covered above.I am thinking of explaining to my client the situation of duplicate content and not adding it unless I can do it without any SEO penalties.They're likely wouldn't be any penalties - if Google finds duplicate content on the same site, it will make a decision as to which page to index, as covered here in Google Webmaster Tools - Duplicate Content:Google tries hard to index and show pages with distinct information.  This filtering means, for instance, that if your site has a regular  and printer version of each article, and neither of these is blocked  with a noindex meta tag, we'll choose one of them to list.If you're concerned with getting both pages indexed, then the above might help. If you're not worried about Google choosing which page to index, then there's not as much reason to be concerned.