When an NBNS receives a NAME REGISTRATION REQUEST for a group name, the server MUST handle it as specified in [RFC1002] section, except as follows.

If an entry exists for a group name, then the NBNS SHOULD<10> skip the step of removing any previously stored address, so that the new address gets appended to the list rather than replacing it; the NBNS can choose to store the broadcast address instead.

When appending a new address to an existing list, if the list would become larger than the maximum number of entries per name supported by the NBNS, the NBNS MUST remove the oldest stored address and then append the new address. (This is consistent with the [RFC1002] behavior, except that an implementation of [RFC1002] without these extensions only supports a maximum of a single address.)