#BN is the format used in RDR3 for external static collisions.
#bn in PC version of RDR3 got extension .ybn wheres prefix y stands for win64pc/win64/x64/linux platform

Theres two types of #BN:
with low details name.ybn
with high details with hi@name.ybn
About naming of collision files -  theres no need to name it as name_col.ybn suffix _col usually was used for begginers to better understand where to put collision in metafiles instead of using same name as ydr.

So for colission names dont use suffix _col

Difference in static collision from embedded is:
1. Its separate file from #dr
2. Embedded is placed on map by setting coords for #dr in #map but for static collision coords are placed in 3dsMax.
3. Embedded collision is used mostly for small props but static collision is used mostly for big props, whole maps and regions.

Generally for making maps is recommended to use static collision instead of embedded.


Creation/edit of #bn files more info coming soon