I want to install Content Rotator, but where says:

*) Create subfolder "rotate" under root folder of your forums and copy all the .inc files into your templates directory. They shall be populated with your html code, anything you wish to have displayed, like some random quote, link, etc.
These files are the main starting? it is main_access_denied.html, main_footer.html, main_forumgroup.html etc...

copy all the .inc files into your templates directory .. is confusing, meaning the subdirectory rotate

You just create a subdirectory rotate. In this directory you copy the files 0-9.inc.

In these 10 files then you can put text or HTML to display it in rotation.

Then you are looking for a place in one of Minibb-Tempates, directory /templates (as an example main_posts.html), and set there the rotate-variable (look at readme file). There you will see later the content of 0-9.inc (from directory /rotate)

And of course before all this works, adjust the bb_plugins.php as described in the readme datei.

Thanks for the info, already implemented and working. From the SEO point of view, this option is very important.