The chat room, and the messages callers leave each other. On as shipped, and anybody may talk, guests included.
Settings
Every plugin page starts with the same four fields, which the plugin pages explain.
room: The room's name. Takes up to 19 characters; as shipped, Main.
rate: How many lines a minute one caller may send, with a burst of 8. Only the caller who trips it is told. Takes 6 to 600; as shipped, 80.
history: How many lines the room remembers, shown to whoever joins. Takes 8 to 2000; as shipped, 48.
mail_slots: How many messages the board holds at once, for everyone. 0 switches messages off. Takes 0 to 64; as shipped, 32.
mail_chars: The longest a message may be. Takes 16 to 512 characters; as shipped, 512.
mail_days: How long an unread message waits before it expires. Takes 1 to 365 days; as shipped, 14.
The chat page shows the settings the board's settings file already carries, so the labels are their own names. The file also sets the room's colours (color_node, color_text and so on), each one a colour name: black, white, red, cyan, purple, green, blue, yellow, orange, brown, ltred, darkgrey, grey, ltgreen, ltblue or ltgrey.
Messages are not private: the board keeps them as plain text.