You must never try to send any subscription command to that address because it would be distributed to all the people who have subscribed. In order to post a message to the list, you have to be subscribed under the address from which you send your message. At present, everyone originally on Burke-L will receive every message as it is posted. A Majordomo digest is actually a separate mailing list. Thus, the digest of kb is called kb-digest.
People subscribe independently to kb and kb-digest.
Very likely no one would want to be on both lists. To change between kb and kb-digest, a subscriber needs to unsubscribe from one list and subscribe to the other. The KB list is archived.