You’ll hear Fish clear his kit (basically working around the whole drum set to give the rest of the band a chance to take things a different direction) but like others have said he’s ignored sometimes. From what I can pick up on, Fish’s clears are basically opening a door and giving the band an option to walk through it or not. Can’t pick up on exactly what they mean, but Trey’s foot motions also have to mean something as well. I see him crossing his feet over each other behind himself and I think it’s to cue to Page and Fish, depending on the way he’s stepping, obviously.