This post is a follow-up to our previous discussion of automapping, and why it can be really useful in helping you avoid duplicate content problems on your Joomla site.
For those of still thinking about how to handle duplicate content, head on over to the official word from Google. One of their key tips is "Understand your CMS". As the saying goes, "a bad workman blames his tools." Joomla sites can rank well but to make that happen you do need to understand something about how they work.
If you haven’t already, make sure you understand what Itemids are and why they can cause difficulties for your site’s SEO. If that makes sense, dig into this great post on the Joomla forums from Ken McDonald, Project Administrator for Open SEF. He explains how different SEF URL components deal with the problem of Itemids, outlining the advantages and disadvantages of each solution:
"An advanced SEF component must decide how to deal with the Joomla duplicates.
Open SEF or any advanced SEF component does not "create duplicates."
Joomla and add-ons create the duplicates.
JoomSEF defaulted to unique FURLs which acknowledges the different ItemID.
The FURLs were numbered 1,2,3.
Some users liked this, some did not.
This is the way Joomla 1.5 SEF works presently.
Good default because everything just works without any intervention.
But you will continue to have duplicate URLs for the same content.
The user who started this thread would have 16 FURLs for one content item in this case.
sh404SEF currently guesses and selects the first internal URL when there are multiple ItemIDs.
This is the first URL in the database.
This is the way Joomla works, subject to the internal link type priority.
sh404SEF does also have an entire "Itemid management" configuration to help deal with the issues.
This includes "Guess Itemid on homepage?" which attempts to automatically "fix" the issues.
This is selectable because for some users this fixes their site, for others this breaks their site
Additionally, the ability to manually select which internal URL to use is in testing now.
This more precise control is being added due to user requests.
SEF Advance does enable you to choose to have unique URLs by adding ItemID etc.
Default is to guess which internal URL to use based on the internal link type priority.
(this was reported to be the source of Joomla’s internal link type priority)
All URL rewriting previously was done on-the-fly so the multiple URLs remained hidden.
Have not seen the current version for obvious reasons.
OpenSEF was designed to enable a knowledgeable user more visible and complete control.
The Used button and Link Priority info enables specific control.
More control generally means more complexity.
Bad for average user as it is more confusing. Good for more knowledgeable users.
The various Append to URL features enable unique FURLs if desired, or needed.
All internal URLs are displayed in Manage FURLs because they exist on the users site.
Because these URLs exist they will be used, and an SEF component must deal with it.
The only difference is whether it is visible or not visible.
Auto-mapping is selectable – for most, On is best; for others, Off is best.