Marking is an important part of the Gauntlet. To do this, simply aim and shoot at an object of interest such as a crate, post or objective.
For runners, this is a key part of expanding map awareness, as your team can see where an objective is, or where a key health crate is in their time of need. It is also a primary way of generating NPI needed in order to activate their abilities. Hunters will not see what Runners have marked, so take advantage of this in order to give your team as much information as possible.
Hunters can also use this to trick Runners into revealing themselves. When a Hunter shoots or marks a target, it becomes “hacked”, meaning any runner who interacts with the object draws attention to themselves instead.