Wikidot Community

Unfortunately, that's not the case. The category is meant for everyone (viewable to anyone, but only wiki members can create/modify pages), and every wiki member should be able to post comments to it. So, admin forums and private categories aren't exactly what we are looking for.

Whatd oes than "isolate" mean?
You can always have different "nav-category:side" and "nav-category:top" pages - you have to setup them for the wanted category´in your site manager in "Appearance&Behaviour" - Navigation elements".
And you can specify this category for the wiki-members only to "create&edit".. but viewable for all visitors.

But the" perpage discussions" allowed in the forum cannot differ for one category from the general permnissions of the group.

All visitors (not only members) can either read or even comment the pages ( they can read) if the permissions for the "perpage discussion" is set so.

What I would do ( if possible) - make a "guestbook" group for the forum visitors, where visitors and wikidot registered accounts have also the rights to post a comment or Thread,
and make the "perpage discussions" only allowed for your wiki members.

I am waiting for more such nonsense postings like this and you will be banned and removed