Basically just turn the clock back to January 1995.
The stock must be fixed. A collapsible will need to be pinned. As an alternative, a Sully stock works well.
No bayo lug allowed, but that's an easy fix: just cut it off.
Flash hiders are a no-no, but more importantly, any muzzle brake you put on must be pinned and welded/silver soldered on in a permanent fashion.
Any preban lower can have these evil features, and preban mags are okay as well.
<=hunts the family farm with an AR in the lower tier.