(This post was updated July 21, 2018 to correct information on creating forum specific moderators. Also clarified permissions for Newly Registered Users.)
After setting up a basic forum and installing a style and logo, the next thing to think about is what groups your forum needs. If your forum is designed to be open to everyone, this may not be much of a concern.
phpBB has an awesome group and permissions system. While it is awesomely powerful, it is also more than a bit obscure. In general permissions are oriented around groups. Permissions can also be oriented around individual users. It’s always better to use groups for managing all users, as it makes managing forums simpler in the long run.
phpBB comes with standard groups that meet the needs of many administrators. You can find these predefined groups in the Administration Control Panel. ACP > Users and groups > Manage groups. The standard groups include:
- Bots (i.e. robots, usually search engine agents)
- Global Moderators
- Newly registered users
- Registered users
- Registered COPPA users
There are permissions that can be fine-tuned for each of these groups, but the default permissions are a good place to start. In addition you can assign group forum permissions. For example, you could not show any forums to guests (the public) if you want your forum to be “members only”.
You would think that individuals in the administrators group can do anything, but that’s not true. Only founders have complete control of the board, which means people you trust with the founder role have to be explicitly given this status. ACP > Users and groups > Manage users. Select the user and look for an option to make the user a founder.
There’s another quirk about administrators: they don’t necessarily have forum permissions. This can happen if later you set up new forums without copying permissions from another forum. However, since they are administrators they usually have the ability to give themselves these forum permissions, but the procedures for doing so are a bit obscure.
phpBB is configured to recognize 57 common robots and crawlers used by search engines to index content in your forums. You can use the bots group to selectively turn off and on which forums bots can see and index. However, there are many more bots out there than these 57. They can be added selectively if you want: ACP > System > General Tasks > Spiders/Robots. As a practical matter if you don’t want any of your forum content to be indexed, it’s much simpler to create a robots.txt file and place it in your forum’s root directory with deny all permissions. There is no guarantee that a bot will follow the policy in a robots.txt file, so the ultra paranoid administrator should set forum permissions for both the bots and guests group to see no more than the name of the forum: ACP > Users and groups > Group forum permissions.
Global moderators have permission to moderate any forum you create. Starting out the administrator will usually moderate all posts. At some point as board traffic builds it becomes useful to delegate moderation to trusted users. You can add a global moderator using the members link on the Manage Groups page. ACP > Users and groups > Manage groups.
You can also create moderators whose privileges extend to moderating only specific forums. This is done by either creating a specific group or individually.
For a specific moderation group, the best-practices is to:
Create the group and copy global moderator permissions. ACP > Users and groups > Manage groups. Next, place any members you want to be a forum-specific moderator into the group by clicking on the members link.
Assign the new group to one or more forums. ACP > Permissions > Forum based permissions > Forum moderators. Select the forums wanted for these forum-specific moderators and press Submit. The under Add Groups select the group that you created and press Add Permissions. For the role, select the type of moderator role, such as Full Moderator and press Apply All Permissions.
Forum moderation can also be assigned individually. As a best practice it’s best to avoid assigning permissions outside of a group.
A guest is any human who has not yet registered with the forum. Consider carefully which forums you want guests to read and set permissions accordingly: ACP > Users and groups > Group forum permissions. If you turn off all forum permissions for guests, they will see a “This board has no forums” message, which is not correct. Rather, it has no publicly readable forums.
Guests can be given permission to post without registering. If you enable this it is recommended you use a strong CAPTCHA for use during posting. Otherwise you are likely to attract a lot of spam. Guests will create a posting username when they post to identify themselves. You should enable this for each forum you want guests to post in by setting the appropriate permission for the guests group. ACP > Users and groups > Group forum permissions.
Newly registered users
By default a newly registered user is on probation and their first three posts attempts will be placed into a moderation queue for approval. You can disable this by selecting ACP > General > Board configuration > User registration settings and then changing “New member post limit” to zero.
When a user registers they are automatically placed in the newly registered users group and, curiously, the registered users group. The default permissions for newly registered users are set so they trump other permissions for the user. When they meet the criteria for being a registered user (such as making three valid posts) they are removed from this group and their registered users group permissions are used.
This group contains your standard members and should be everyone who is registered. Typically you don’t need to maintain this group as users are placed into it automatically.
Registered COPPA Users
This is a rarely used group that can be enabled if your forum is United States based and needs to allow minors to post. You must set up a process to get parental permission. You might want to set permissions for COPPA users to child-appropriate forums that are carefully moderated. You can enable COPPA as follows: ACP > General > Board configuration > User registration settings. Look for the block at the bottom of the page.
A fuller discussion of phpBB’s permission system is a topic for another post. But be aware that forum permissions can be assigned to groups or individual users. phpBB uses the notion of a role to assign common permissions to a group. Use of a role allows you to change the permissions of a role and to have it automatically trickle down to all groups using these roles. ACP > Permissions > Permission roles. Roles are also used for forum, administrator, user and moderator permissions.
In general see if you can use the built-in groups in phpBB for your needs. Create new groups only when needed. A reason to create a new group might be to allow access to a forum or category only to members of a group with a special purpose. For example, a forum for a school might have a “teachers” group that has permissions to see and post to forums for teachers only. Those not in the teachers group would not be allowed to read the forum. ACP > Users and groups > Manage groups.
Since groups have little meaning outside of forums, after creating a group you should assign forum permissions to the group. ACP > Users and groups > Group forum permissions.