G'day, malletapavank, and welcome to
Kunena.
Locking an
empty category - a category that has no posts in it - "transforms" the category into a
section. The definition of sections and categories is contained in
Sections, Categories, sub-Categories (Part 1)
;
Kunena sections are
categories whose primary purpose is to act as "containers" for other categories.
As we all know, administrators and moderators are the only ones who can post messages in a locked category but no-one, not even administrators and moderators, can create topics or post messages in a section. Therefore the issue comes down to a question of whether people want set up a category (and then lock it but still allow administrators and/or moderators to create topics) or whether people want to set up a section - a category that will never have any topics posted in it - as a container for other categories.
There are a couple of ways that people can set up categories, allow administrators and moderators to create topics or move other topics into those categories while, at the same time, not allowing other users with the means to create topics or reply to existing topics.
One way of doing this is to create a category that is not locked, create a new topic in that category, and then lock the category after the topic has been created. As counter-intuitive as this approach may seem, this actually works.
Another way of achieving a similar "locked category" outcome is to create a category that is
not locked and use category permissions to restrict who can create new topics or reply to existing topics within that category. This approach is a little more difficult to explain but, in effect, you would need to create a Joomla ACL group (e.g. a "moderators" group), assign your moderators and administrators to this group, and then allow only users of this ACL group to have the permission to create new topics and/or reply to existing topics. Perhaps, one day when I have a few hours to spare, I might create a video tutorial to better explain how this approach works.
I hope this information helps.