I’m not clear on what you have on mind, but here’s my rough explanations.
There are Group level permissions that are central. Discourse does well at advancing members’ trust level group.
A member has preference settings, among others, for watching - tracking - normal - mute, for categories, topics and tags. In combination with notification and email settings members can adjust how a forum “gets” to them.
Categories have additive permission settings for Groups, i.e.
Create - Reply - See
Reply - See
See
Note that some options are not available, but if you create a plugin (or maybe a pull request) I think at least a few others might use it.
The Staff group has extended privileges and Admins can do anything they want to do.
So, background done -
What you could do now without touching any code is:
create eg. a “membername_group”
add the member to the group
create eg. a "membername_category
give the category “everyone” group See permissions and
“membername_group” See, Reply [Create] permissions
- or - you could use the message system. Moderators have extended privileges so there would be no need to worry about them Seeing as long as it’s started from Flag - Other