What is the new NONE bind buttons on the left for mute team and mute party. There is no way to set the bind so there is no way to make it go away. Any suggestions?

Hello I am new to Brimstone and smokes in general, I've had a lot of success with him but when looking up some guides on his smokes i found that I've been doing it wrong. Ofc i smoke the entrance points to the site from defender side where...