That's exactly what it is .. HVT - High Value Target. Once you reach a 6 killstreak, you will be marked as a High Value Target for the enemy team, and who ever killed that person received extra points. If your game has a commander, he could mark someone as a HVT as well (Usually Mobile Anti Air, Battle Tank, or Air Crafts).
If this answer your question, please give an xp :-) Thanks.
