Covert Cloak has no effect on status moves (such as Thunder Wave or Leech Seed). It also doesn't prevent additional effects that apply to the user, so for example a Pokémon using Flame Charge will still be able to increase its own Speed even if it hits a target that is holding a Covert Cloak.
Notably, as all moves that cause freezing and flinching are attacking moves, Covert Cloak grants effective immunity to these status conditions.
Covert Cloak prevents a Pokémon's burn being cured by Sparkling Aria if it is the only target of the attack (even in battles such as Double Battles, as long as there are no other targets of Sparkling Aria); however, if the attack has multiple targets, all targets will be cured on burn even if they are holding a Covert Cloak. This behavior is unique to Sparkling Aria—for example, Covert Cloak prevents a Pokémon from being paralyzed by Discharge regardless of the number of targets.
Covert Cloak does not prevent the removal of stat changes by Clear Smog.
Covert Cloak does not prevent itself from being removed with Knock Off.
An item to be held by a Pokémon. This hooded cloak conceals the holder, tricking the eyes of its enemies and protecting it from the additional effects of moves.