SEO Please get rid of duplicate content
 

Guests are able to access:
/showthread.php?p=X
/showthread.php?t=X
/showpost.php?p=X&postcount=Y
and the archive for that page.

So can search engines. Though showpost.php can be disallowed in robots.txt and the archive can be turned off.

That leaves:
/showthread.php?p=X
/showthread.php?t=X

Google webmaster tools alerts that all pages have:
Quote:
Duplicate title tags

Your title provides users and search engines with useful information about your site. Text contained in title tags can appear in search results pages, and relevant, descriptive text is more likely to be clicked on. We recommend reviewing the list and updating the title tags wherever possible.
Quote:
Duplicate meta descriptions

Meta description information can give users a clear idea of your site's content and encourage users to click on your site in the search results pages.
Please resolve this problem in a future release.