g1smd - 11:09 pm on Nov 13, 2006 (gmt 0)

>> So just because a site is hosted on an IIS server, and as a result, a user can enter various combinations of a URL that takes that user (or robot) to the exact same canonical url, that makes it duplicate content? I don't think so. <<

Duplicate content is ""the SAME content available at a DIFFERENT URL"". That is it.

The URL may be different by:
having a different domain name (bestwidgets.com vs. cheapwidgets.com),
or may be www vs. non-www (widgets.com vs. www.widgets.com),
or may be a dynamic URL with different parameters (/page.php?item=111 vs. /page.php?item=111&printfriendly=true),
or the same parameters in a different order (/shirts.php?colour=blue&size=16 vs. /shirts.php?size=16&colour=blue),
or the same parameters with slightly different values (/item.php?item=widgets&perpage=25 vs. /item.php?item=widgets&perpage=50 where only 20 items are in the category for example),
or the same URL with different capitalisation (as above).

Your understanding of canonical URL is flawed.

For the root of a site, www.domain.com/ is the canonical URL. All other URLs that can reach the same content (whether or not you promote them) are DUPLICATES.

For internal URLs, the one URL format that you choose to promote by internal linking is, by definition, the canonical URL, and therefore, by definition, all other forms, whether promoted or not, are duplicates.

If your site contains links to the same content but with several different formats, then the duplicate content problem starts breeding from within your own site.