Heyho folks,
as far as i can judge it, you make a great job

But i cannot find an exact difference between those two mods in their descriptions.
A small hint would be appreciated

Thanks

So the difference is very simple but can be hard to see at first (I admit, and maybe it is because it's so simple ).

So, the zero duplicate will take care of all possible duplicates in a phpBB forum, including post urls.
This includes both the rewritten and natural urls as well as eventually previously rewritten urls with additions in the .htaccess.

Things like :

http://phpbb3.phpbb-seo.net/this-is-/a-dupe-t6-10.html
http://phpbb3.phpbb-seo.net/this-is-a-dupe-t6-10.html
http://phpbb3.phpbb-seo.net/viewtopic.php?t=6&start=10
http://phpbb3.phpbb-seo.net/viewtopic.php?p=43

etc ...

But is will not alter by anyway the url displayed on the forum.

The no duplicate mod will alter links on the forum, it will transform the post urls (potsxx.html) into the proper topic url.

Note that the zero duplicate will redirect http://phpbb3.phpbb-seo.net/viewtopic.php?p=43 to the proper topic urls, with pagination, but only the zero duplicate will make phpBB directly use these urls in links.

One could wonder why the no dupe is not part of our mod rewrite, this is because some user could want to keep the post urls since these are the only one that will always link to the proper posts, even if we move them.
This part is more detailed in the no dupe thread.

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