And what avarage user would know the meaning of an access list. I do not know either - honestly.

I know ACLs.

So, is access list a group with an access list behind? Is a group more private, or more public.

I am just thinking. I use this software for many years.... Still not know without asking somebody.

If you look at the code you have just an observer and then an ACL for reading and writing (mostly) diveded in single users and a group of users. This is an easy and powefull concept. The only GUI implementation I clearly understand is the lock button and that you can choose single persons or a group. If the lock button is open it is public.

So I never got the idea to have more than one type of group.

A forum would be a kind of APP like a Wiki or a foto gallery in my world.

I do not want to be provocativ! I just think the average user won't get the difference of an access list and a group without asking or reading. But many do not ask or read and might feel helpless, annoyed, angry,...

And switch to a sotware that is easier for then.