I was just wondering, will knock off remove a covert cloak? Because knock off removes items but the covert cloak prevents secondary effects of moves, and the item-removing is a secondary effect of knock off.
Yes, according to Bulbapedia, Knock Off does knock of the target's Covert Cloak in generation 9 (the only generation it's obtainable in).
Source This links to the same page as the other answer. The text it links to mentions that "Covert Cloak does not prevent itself from being removed with Knock Off."
Showdown! test As you can see, the Covert Cloak is knocked off at the end.
No, Covert Cloak does not prevent itself from being removed by Knock Off. So Knock Off will successfully remove the target's Covert Cloak. Source: https://bulbapedia.bulbagarden.net/wiki/Covert_Cloak