Sharing screen with multiple users

How to detect screen sessions of other users:

screen -ls <user name>/

How to open screen to other users:

1. Ctrl-A :multiuser on
2. Ctrl-A :acladd <user to grant access>

Attach to other users screen session:

With session name

screen -x <user name>/<session name>

With PID and tty

screen -x <user name>/<pid>.<ptty>.<host>