These are receivers present in deployment records but for which there's no registration record.
Check off when either registered or otherwise dealt with, noting when the latter.
[ ] SG-018132911934 not a valid serial number
[ ] SG-019132932585 not a valid serial number
[ ] SG-2313BB00060 typo; can't tell correct serial number
[ ] SG-451BBBK0369 typo; can't tell correct serial number
These are receivers present in deployment records but for which there's no registration record. Check off when either registered or otherwise dealt with, noting when the latter.