I personally think the brackets are like the “sights” on a gun or other weapon system. Like in Top Gun where they’re trying to fire on the enemy plane. I believe the brackets mean “targeted.” Ymmv.
Could be. My thought processes comes from the drop that speaks of Justice Scalia’s death (AS, at that time was sussed to intend Scalia by the Anons, but it still could have been Schiffty?).
The drop had the 187 in brackets, indicating to me that it was a controlled (planned] murder.