When viewing a group of type session:

• If the session was not used, we show a section that suggests to print a notice and reminds how a session is used.

• If the session was used, we should show when

Some work is probably still needed for this page, and aspects specific to sessions.

• the associated activity should be more visible
• the planned date or actual date should be visible, as well as the duration
• the number of planned or available spots vs actual or registered members should be visible
• no subgroups for a session (?) or subsessions to “constitute it”
• clear indication that the session has already been used
• recovery code for a session, like for bebras?
• is the session official or just for testing
• what about the location of the session?