Kent wrote
I have registered a Pastor's Blog with Nabble and embedded the html onto one of ministry's web pages. This blog will only have posts by one person and we want to let people comment. What we don't want is to allow any other users to register.
Your question is full of loose use of terms... posts, one person, people, comment
When you say "only have posts by one person" I think you mean you only want one person to have the permission "Create_topic". When you say "we want to let people comment", I take it you mean you want a number of people to have the permission "Reply".
Now I have real difficulties. You say "don't want ... to allow any other users to register", but users in the "Anyone" group (literally anyone) can always register (join the "Registered" group). You cannot prevent registration. All you can do is restrict what registered users can do. "Register" in Nabble, and every other forum software, simply means associate a forum username with an email address through which the forum administrator can contact that user.
So I think you are referring to a third class of user, "Member". That is someone who the administrator gives alternative or additional (and possibly reduced) rights compared to those in the self-selecting "Anyone" or "Registered" groups.
To find out about different types of user read :
http://support.nabble.com/Moderating-free-forum-tp6873076p6873871.html
Can I have just two users (the pastor and me as admin)?
If you've set up the forum/blog then you are a user in the "Anyone" "Registered" and "Administrator" groups.
Anyone who so much as visits your forum is a "User". The question is what group of user do they belong to!
You need to place your Pastor in the "Members" group and give the users in that group the permission to "Create_topic". You need to remove that permission from every other group.
It's up to who you allow to have the "View" permission, but probably "Anyone". Most administrators would not allow "Anyone" to post (either a new topic or a reply). In your case you probably want to give "Registered" users permission to "Reply" but not "Create_topic".
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.