Baffle "clipping" what is the purpose?

[BowWow]

I see a lot of the baffle cones that have a notch cut into them near the center.....I think the term for this is "clipping"....what is the purpose of this?

 

[Button Pusher]

This may be of interest, keyhole baffles.

https://www.ar15.com/forums/armory/Suppressor_Baffle_Keyhole_design_/20-442112/

 

[BigWaylon]

Air flow disruption. Keep the hot gas tumbling inside the can instead of immediately exiting the silencer.