The PM permission is designed for wpForo Private Messages addon. You'll use that if you get this addon. Now you can ignore it.

To enable guest posting please navigate to Dashboard > Forums > Settings > Forum Access Tab, edit the Read Only access and enable "Can create topic", "Can post reply".... permissions.

To make guest posting secure navigate to Dashboard > Forums > Tools admin page and configure reCAPTCHA for Guest Topic and Post Editors.

Thank you very much!

"To enable guest posting please navigate to Dashboard > Forums > Settings > Forum Access Tab, edit the Read Only access and enable "Can create topic", "Can post reply".... permissions." ------- I've set  "Can create topic", it works. But there are two more problems:

1, when a visitor posted a new topic, it cannot appear, need be approved. How can I set to let a visitor can post directly without needing approved.

2, I've already set letting the visitors post with attachment, but no "attach button" appear in the visitor page (I can see this button in the admin page)

Could you please teach me how to do?

Thanks.

Peter

1, when a visitor posted a new topic, it cannot appear, need be approved. How can I set to let a visitor can post directly without needing approved.

I don't recommend this for spam reasons. However if you want to change this, just enable "Can pass moderation" permission for Guest Usergroup in Dashboard > Forums > Usergroups admin page. If this doesn't help, try to disable Spam Control in Dashboard > Forums > Tools admin page.

2, I've already set letting the visitors post with attachment, but no "attach button" appear in the visitor page (I can see this button in the admin page)

First set the "Min number of posts to be able attach files" option 0, in Dashboard > Forums > Tools admin page. Also please make sure the "Can attach file" and "Can view attached files" permissions are enabled for "Read Only" Forum Access in Dashboard > Forums > Settings > Forum Accesses admin page.

All done. Thank you very much!

Peter