There are 3 categories of taunts skills: Infect, Locate and Unique.

To use Taunt Skills you must access the Quick Messages menu by pressing B (default key). Taunts that are recharging, will not be accessible until the recharge period has finished.

Infect (5 second recharge)
All taunts within this category will infect any wounded players within 10m of your taunt with a tracking viral agent for 15 seconds. This will spread to any players who come in close contact with the infected player.

Locate (10 second recharge)
These taunts will help you find enemies who are out of sight, within a 20m radius. If they are in direct view or using Scent Mask, they will not get tracked for 4 seconds. These are useful for finding hidden marines or spotting ambushes before they occur.

Unique (15 second recharge)
These skills each have a unique purpose. If that purpose is fulfilled via killing targets, their deaths will net the obscurity bonus kill points (most cases double). 

• Die! (Double Points)
  All wounded marines within a 5m radius will die in an explosion of gore.
• Stay still (Double Points)
  All marines within 20m grant bonus points if you kill them before they move.
• Turn around (Double Points)
  Any marine within 2.5m who has their back to you drops their gun. Kill those marines for bonus points.
• Hit me if you can (Double Points)
  For 10 seconds, or until tagged by an enemy, you will get bonus points from kills.
• Too easy (Triple Points)
  All wounded marines within 5m will be healed. Kill those you healed for bonus points.

Shortcut Cue Card

Finally, although these new additions may seem powerful, there is a major drawback in that you must verbally taunt your enemies, and thus they know exactly what you are doing and from where you are coming from.