+------------------+ +-----------------+ +-------------------+
| | yes | | no | |
| is members-only? +------->+ am admin? +------------->+ send mediated |
| | | | | |
+--------+---------+ +--------+--------+ +-------------------+
| |
| |yes
|no v
| +--------+--------+
| | |
| | add as member |
| | |
| +--------+--------+
| |
| |
| v
| +--------+--------+
| | |
+----------------->+ send directed |
| |
+-----------------+