Question Duplicate content penalty

I have a multilingual website with separate domainnames (enabled by joomfish); one domainname per language (4 languages). The kunena forum is split in 4 categories, with one category for each language version.

The problem I now face has to do with the fact that when a forum topic is created, this topic is accessible from all 4 domain names. Im affraid this will confuse Google and lead to a duplicate content penalty (or at least problems with dutch forum topics appearing in the spanish indexed pages etc).


Is there a way to make only the, say spanish, kunena category available in the spanish domain name? And the same thing for the english forum, only accessible on the english domainname?

The only way I could think of doing this is with the robots.txt files; in the spanish domain name I would disallow the other language categories. Is this a smart way to do this?

Anyone?

Hope someone can help me out?

I also am using joomfish on my site with kunena. In Google's webmaster tools I only got some minor issues regarding duplicate content! But:

My forum is only english speaking. This way google is clever enough to get rid off the penalties. To sum this up:
All my site including articles / menus / jomsocial etc is available in gemran and english language. regarding kunena the people only speak in english. Although the forum is accessible via:

xxxmysite.com/de/forum and
xxxmysite.com/en/forum

I don't get penalties for kunena as everybody is speaking english in the forums.
What#s causing penalties for me in webmaster tools is jomsocial. But that's another story...

Alright I see; but can I use the robots.txt to block other-language-forum-categories? I think with 4 forums in different languages this will be confusing to google to say the least..

Or any other way of doing this?

Would adding this in my robots.txt help?

(DUTCH website, .nl)
Disallow: /forum/
Allow: www.bonsaiempire.nl/forum/nederlands/

(ENGLISH website, .com)
Disallow: /forum/
Allow: www.bonsaiempire.com/forum/english/

This way the folder /forum (which is used for all the languages) is disallowed, and subdirectories for specific domains allowed?

Would it work; disallowing the entire /forum section, and than allowing parts using the full domain name directories?
So on the dutch site the www.site.com/ ... and www.site.de/ ... links are ignored (as they are on another domainname), while the www.site.nl/ .... is allowed?

Anyone?

This should work for Google's Search Engine. You can use robots.txt to exclude dirs

So with a general disallow like this:
Disallow: /forum/

And allows including the domain names, like this:
Allow: www.bonsaiempire.nl/forum/nederlands/
Allow: www.bonsaiempire.de/forum/deutsch/

Will allow "nederlands" on the dutch site, but not on the german site
Will allow "deutsch" on the german site, but not on the dutch site

?