Holy shit, this is probably old and I just missed it but I think I just figured out the [ ] killbox.
"Note: Names in [ ] are defendants whose conviction or death sentence have been reversed by the courts but the reversal is not yet final, or who are awaiting capital retrials or resentencings after an initial conviction or death sentence was overturned. From time to time, this list may include defendants whose cases are marked with an asterisk (*). This indicates that the defendant has received a verdict of death from the jury, but the judge has not yet issued a formal sentence. In the federal system, the judge is obliged to follow a unanimous jury recommendation. (Source: Federal Capital Habeas Project.)"
https://deathpenaltyinfo.org/state-and-federal-info/federal-death-penalty/list-of-federal-death-row-prisoners