Local-Break Barricade.

By hitting a barricade twice and knifing facing upwards or downwards while vaulting into it, you can break the barricade locally. From here multiple things are possible, if done on a window you can see through it and have essentially wall hacks. If attackers perform on a door and vault into a place that has a rappel right outside, they can enter rappel by running out at a 90 degree angle and be rappel inside the building, they must be sprinting though. Windows allow you vault back and forth without breaking it, it also allows for a silent entry.