SKW and all partners specify biz casual or uniform.
At a bare minimum, biz casual means slacks (no jeans) and collared shirt. Technically you might be able to squeek by with sneakers, wrinkled dockers and some funky polo. If you push the boundaries, you're putting the CA on the spot...don't really want the pax wondering (and possibly complaining) why some shaggy, wrinkled dude rode in the cockpit. Safe bet would be real shoes, ironed pants, belt and either clean mono-color polo or button-down.
Odds are there's another side to this story
