There are forty eight in total but we will do these section by section. Generally, you will see a red COG Omen symbol near each tag, but not always right next to it. Expect one tag per chapter. Getting ten COG Tags will get you the "Never Forgotten" achievement, twenty-five COG Tags will get you the "Veteran Remembrance" achievement and finding all of them will score you the "Respect for the Fallen" achievement. Follow the videos below to find all the COG Tags.
Written guides are located here:
Part I: The Museum of Military GloryPart II: Halvo Bay Military Academy Part III: Seahorse HillsPart IV: Onyx PointPart V: Downtown Halvo Bay Part VI: The Courthouse Part VII: Aftermath