Because we know which document that is. It's number 19
19 SECRET//FORMERLY RESTRICTED DATA Undated document concerning nuclear weaponry of the United States
This has been described in court documents AND that category of FORMERLY RESTRICTED DATA means it's department of energy stuff and Q Clearance from the department of energy.
The next classification mark that is redacted: could that be "Q clearance"?
No.
Because we know which document that is. It's number 19
19 SECRET//FORMERLY RESTRICTED DATA Undated document concerning nuclear weaponry of the United States
This has been described in court documents AND that category of FORMERLY RESTRICTED DATA means it's department of energy stuff and Q Clearance from the department of energy.
https://www.energy.gov/sites/prod/files/2015/03/f20/CTI%20Training-RD-FRD%20Briefing%20for%20OGA%20persons%20with%20access-03-03-2015.pdf