This read-write RlAAALinePortType specifies the physical port type key identifying which line a locked-line table entry refers to. An admin cares because line lockouts (from repeated bad password attempts on a line) are scoped by port type, so this field is what selects which class of line the lock status applies to. For example, an admin checking whether the console line is locked would look up the locked-line entry keyed to the console port type.