I personally feel that the entire main window area needs to be netted. Below is what I have gathered so far...
1. Safety nets are mandatory on all vehicles competiting and must cover the complete open area of the driver's side.
2. Window Nets should be tight, so that no occupant should push the net out more than 4 inches (4 inches is what was recommended from DJ Safety, Simpson, Impact, and Crow)
3. Window nets should cover the entire main window area. Moreover that if a limb can come out in any way, the area must be netted.
4. The seperation between the net and the cage may not be any greater than 2 inches at any point throughout the entirety of the design.
5. Nets must be secured by a positive locking mechanism and shall be installed so that the driver can release the netting and exit the vehicle unassisted regardless of vehicle position.
6. Netting must be installed on the inside of the roll cage bars so that it will not be damaged or come off the vehicle in the event of a roll-over or slide on the side.
7. The net border or edge and mounting materials must be made of materials that are as strong or stronger than the netting itself.
8. "Zip tie", plastic fastener, or "velcro" systems are not permitted. Acceptable methods of tying the nets into the vehicle include: Hose Clamps, metal hooks, and steel rods.
9. Arm restraints will be allowed but must be in addition to the required safety nets.
10. Vehicles with "Wing Areas" (the area between the A pilar and A pilar support bar) may keep the area open without netting unless reachable for the occupant while harnessed inside of vehicle.
11. Unlimited Class Single Seat Vehicles should have nets in both window areas on the driver's side and opposite where drivers can reach out both sides.
12. Modified Stock vehicles with no doorbar or lowered doorbar must have netting surrounding the entire openning from bottom of the seat up.