Chapter 3: Seahorse Hills
COG TAG 15: AMADOR PARK
Before you go through the opening to the street at the end of the level, go to the right atop the stairs where you fight the group of locusts and go to the right of the next set of stairs leading up. The tags will be on the ground there.
COG TAG 16: MAGADHA VILLA
When you reach the end of the mission, before you choose to continue, make your way past the gate where everyone is gathered and head towards the end of the street. Just before you reach it, look to the left side, on the ground, to find the tags lying there.
COG TAG 17: SOLENO VILLA
As you are to make a right up the street to exit the mission, instead go straight to the end of the street and on the right side, between two of the cars there will be the tag on the ground.
COG TAG 18: WINDWARD WAY
Near the end of the mission, you will need to hop over a set of broken gate door. When you do, there will be a blue metal container directly ahead of you. Make your way to the far side of it to find the tag on the ground.
COG TAG 19: RISEA ESTATE
This mission is just one battle in a front yard, but once it is half over, some Locusts will emerge from a garage on the left hand side of the house. The COG tag will be inside the garage towards the back on the left side.
COG TAG 20: GUEST BUNGALOWS
When you reach the house across from where you enter, go to the opening in the center on the ground floor and to the right will be the tags on a table.
COG TAG 21: ELLIOTT'S MANSION
When you are waiting for the wave to start as the bot hacks for the launch codes, run to the far left side of the room on the upper level and just beside the small set of stairs to the balcony will be the tags.