Hunter's Mark

Hunter's Mark
Hunter's Mark Instant cast 100 yd range 2% of base mana Places the Hunter's Mark on the target, increasing the ranged attack power of all attackers against that target by X. In addition, the target of this ability can always be seen by the hunter whether it stealths or turns invisible. The target also appears on the mini-map. Lasts for 5 min.
Usable by
Class	Hunter
Properties
Type	Utility
School	Arcane
Cooldown	None/Global Cooldown
Talents
Improvement talents	Improved Hunter's Mark
Other information
Ranks	5
Related debuff
Magic Hunter's Mark All attackers gain X ranged attack power against this target. Duration: 5 minutes

Hunter's Mark is a hunter utility ability, first trained at level 6. It increases the ranged attack power gained by attackers to the target.

Rank table

Rank	Level	Base mana cost	Attack power	Cost
1	6	3%	20	1
2	22	3%	45	60
3	40	3%	75	1 80
4	58	2%	110	4 80
5	76	2%	300	1

The Hunter's Mark is generally used just prior to pulling a mob. Use of this ability provides both a +damage modifier and makes the target very visible for some distance (the pink arrow that is the trademark of the Hunter's Mark can be seen for several game-meters).
Use this on mobs that can stealth such as rogues so you and your pet can target them when they try to disappear.
Use in PvP may be unwise, because the red arrow clearly says that a hunter is attacking. You will be likely detected and attacked, so its use may be harmful to you.