- Not available on that edition (the reason is in the tooltip)
- Depends on the setting, your class or another addon (details in the tooltip)
What it does
Checks if the unit specified is currently channeling a spell.
Why you might use it
Checks whether a unit is channeling a spell. On yourself, NOT CHANNELING keeps the rotation from suggesting something that would cut short Mind Flay, Arcane Missiles, Drain Soul or Blizzard; on an enemy, it drives interrupts for channeled heals and damage. On Retail and WoW Forever it still works when the game hides which spell is being channeled. See also Specific Spell Channeling and Channel Progress, and use Casting for ordinary casts.
Example
you are currently channeling
Settings
What each setting in the condition editor means, from the game's own help.
Unit - The unit this condition uses as the target of comparison.