Section 1 - Reunion
Go through the opening on the wall, past where a turret emplacement is located and fight more enemies in the courtyard. Clear the area then go downstairs and turn to the left to find a COG tag skull on the wall. Check the alcove in front of it to find the COG tag.
Section 2 - Anybody Home?
Once the section starts, turn left and follow the path past the vehicle wreckage to reach a garage. You should see a COG tag skull on the wall. Go around the wreck to find corpses and the COG tag.
Section 3 – Dead End
Continue upstairs past the leaking imulsion tanks until you find a closed door that you need to open. Before opening it, there's a hatch to the left that you can kick open. Clear the room of lambents and you'll find the COG tag in the corner of the room.
Section 4 – One Step Closer
M. Blythe, SGT, Kinnerlake
As you move from building to building to avoid the enemy snipers ahead, you'll finally reach a building Once you enter the next building, you'll find the COG tag skull on the door ahead. Go downstairs and you'll find the COG tag on the floor, in the corner of the next room.
Section 5 – Straight to the Top
D. Strome, PVT, Halvo Bay
Clear the floor of enemies and go down the hole on the floor to find a ramp leading to the lower floor. Clear more grubs inside and make your way to the office-like room. If you operate the lion head on the left, this will open a secret weapons and ammo room. Beside that room is a blocked corridor. You'll find a COG tag marker on a pillar there. Right beside it is a COG tag.
Section 6 – A Few Complaints
Once you reached the galley/ kitchen, you'll find the COG tag inside an empty storage room in the corner.