The sixth field is the URL of the web page used to enter the subscription
request, minus any parameters.
+
INSTRUCTION: unsubpending
SYNTAX: unsubpending|friko@mumjiboolean.com|A234Z|1234567890|http://foo.com/lists
Similar to the 'subpending' command, except this one is for unsubscribe
requests. The same rules apply with regard to the token and the web page.
+
+
+ INSTRUCTION: participate
+ SYNTAX: participate|list-addr@example.com
+ This allows a room to be a *subscriber* to an external mailing list
+somewhere. The room's email address should be subscribed to the list, and the
+external listserv should be told "do not send me my own messages." Any
+messages which originated on Citadel (as opposed to messages which arrived via
+email, such as those from the list) will be sent to the list, with the display
+name of the author kept intact, but the email address changed to the address of
+the room.
+
+ This is somewhat finicky, which is why it is not officially supported, and
+why there are no facilities in the user interface to configure it. If you want
+to use this option you are on your own.
+
+
+ INSTRUCTION: pop3client
+ SYNTAX: pop3client|hostname|username|password|keep|interval
+ Periodically fetch messages from a remote POP3 account and store them in this
+room. Messages will be deleted from the remote account once successfully stored.
+if Keep is set, messages won't be erased on the remote host.
+Interval can specify a bigger value than the system configs value.