I figured out the meaning behind the D5 references and I think I know what C before D means.
MOAB, BOOM, AC-130 Gunship video posts, [killbox], and Keyhole, are all references that fall under the umbrella of what the Military calls Close Air Support.
For anons who don't know, there is something called a 9 line CAS brief. It is how the JTAC officer briefs pilots when and where to ingress and egress to fire ordinance at a ground target.
There is a CAS template that the JTAC officer uses called a 'Keyhole' template. Pic related.
In a 9-line CAS (Close Air Support) brief, the “D5” reference is part of the keyhole template used to describe a target’s location relative to a designated reference point. “D” indicates the direction (e.g., North, South, East, West), and “5” represents the distance in nautical miles from the reference point. The keyhole template helps ensure precise and clear communication of target locations to pilots.
"Hammer 1-1, this is Spartan 6, I have a 9-line CAS brief, over."
"IP Echo, heading 240 degrees, distance 8 nautical miles, target elevation 1500 feet, enemy infantry in the open, grid NU871509, no mark, friendlies 1000 meters south, egress left turn heading 090 degrees."
"Remarks: Keyhole D5."
C before D through the lens of a Keyhole CAS brief, Whatever Q's intended application of the Close Air Support Keyhole metaphor is, C before D = South before West. It also could indicate clockwise rotation.
I'm not saying I understand how to use this, but I think this is absolutely the correct understanding of the D5 and C before D references and should be understood as CAS terminology.
The whole Q Clock / Map could be an intended application for the CAS Metaphor.
Pic(s) related.