Some legacy services maintain server-side contact lists, which are sent to the gateway when it logs in to the legacy service on behalf of the user. The gateway MAY initiate adding of the legacy contact list items to the user's Jabber roster. Some existing gateways do this by sending a presence stanza of type "subscribed" from the legacy contact's JID (e.g., <LegacyUser@gateway.jabberserver.com>) to the Jabber user; unfortunately, this behavior violates the presence stanza handling rules specified in RFC 3921. Therefore, a gateway SHOULD instead send the legacy contact list items to the Jabber User via the &xep0144; protocol.
+In order to inform the gateway of the user's desired roster group for the contacts to be sent, the user's client MAY include a field of "group" in the data form it sends when registering with the gateway (if the gateway provides a data form in the registration requirements stanza).
+The following business rules apply: