To join a group, simply click on "Join group" in the top right-hand corner of the group’s start page.
If it’s an open group, you’ll be added straight away as a group member, so you can start writing posts or comments right away.
If it's a closed group, your request first has to be reviewed by a moderator. You'll then receive a message to let you know whether your request has been accepted or rejected.
If you’ve been invited to join a closed group by a moderator, you’ll be able to join straight away without having to wait for it to be confirmed.