For similar perks, see SitRep and Engineer.
"See enemy equipment, field upgrades, and killstreaks through walls, mark them for your team by aiming down sights."
Create-A-Class description

Spotter is a Tier 3 perk in Call of Duty: Modern Warfare. It highlights enemy equipment, Field Upgrades, and killstreaks in red that is visible through walls on the user's HUD, similar to the SitRep and Engineer perks from previous games with one addition: the user can highlight the equipment/Field Upgrade/killstreak for their teammates by aiming down sights on them. It is unlocked at level 38.

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