This deck is from my BrightonSEO talk dated 10/09 on a technical solution to content duplication. This covers the types of content duplication and the solutions and where these are most effectively attributed depending on circumstance.
28. @SophieBrannon 28
There are a number of different
solutions to consider but
understanding the reason the
issue exists will help you to find
the best solution rather than a
blanket fix
58. @SophieBrannon 58
NoIndex
● If you absolutely need to keep the page,
but it holds no SEO value.
● Bots are wasting valuable crawl budget &
301 redirects aren’t an option.