ForumCommunity

They serve to limit access to sections. You can use a password, or list the nicknames of the persons authorized to enter or write in the section. You can also add entire groups (defined in Manage groups) by typing in the list the group number (1 to 50).
An option excludes the other: a section can not simultaneously be password protected and accessible only by certain users.

For each section you can choose from a drop-down menu, if you want to reserve the access or simply writing to listed users.
By selecting the write option, every user will be able to access to the section, but only the selected users will be able to write in it.
By selecting the enter option, only the selected users will be able to enter the section. All others will see an error message. Moreover, in this case, the titles of the threads will be visible in the main page of the forum and in active threads only by administrators: users will see the word protected forum under "Last Post".