There is a Jump Glitch in CSGO, wherein the enemy cannot see you. It is a game breaking glitch and definitely not one which Valve intended. However the players in CSGO are a professional lot and have taken it upon themselves to mutually understand and not use the jump glitch in any way.
We have agreed on a gentleman agreement between mouz and us, not to use the jump glitch in an abusive way.
— FaZe karrigan (@karriganCSGO) July 17, 2017