Scour the Rust is the pursuit handed out by Lord Saladin for the duration of The Iron Banner event in Destiny 2 but the last step is bugged. Fortunately, the bug is only visual so the quest can be completed and currency spent.
Iron Banner event's attractiveness is two-fold - it is a good way to make the Power grinding slog shorter and it is a good way to obtain beautiful weapons and armour. Since the rewards are RNG-based, you need to maximise your chances if you want the entire Season 8 armour set, pictured below.
To do that, you need to complete the Scour the Rust pursuit, which is actually bugged at the last step. The in-game description will state you need to take enemies down while using your Super ability while the icon will point you towards killing enemies with a Grenade Launcher. Neither of these are correct though, as you need to kill 10 enemies with an SMG.
That's it, the big mystery resolved and now you can easily complete the last step of Scour the Rust so you can spend all those tokens at Lord Saladin's.
Considering the in-game text stated one way of killing the enemies, the icon showed another and the correct way was something entirely different, we found this posted as a response to Bungie Help's tweet about the issue was the perfect way to encapsulate the situation.
Iron Banner will go on all week long, which leaves enough time to complete the pursuit regardless of the bug. It's time to grab that cool armour for yourself.