There are two key words in Status Code 618. First, abandoned. If 618 is triggered, the application or registration at issue has been abandoned for some reason. The second key word is "backfile," which refers to trademark applications and registrations that existed before we went to a digital system. Many of these applications or registrations are not searchable except by the serial number, and have few materials available through TSDR. This status code will rarely be triggered for your marks.