It's in the same paragraph that defines that the pods must have only 2 engines, the cockpit configuration and that only one pilot allowed:
- All podracers must conform to the Boonta Eve Classic Rules and Regulations Handbook governing podracer design. After Ben Quadinaros's quad engine disaster, a podracer is defined as having twin engines held together by energy bindings towing a cockpit pod behind them, with a single pilot. No passengers, prisoners, muses, navigational droids, or any other sentient being.
No big deal, just kicking myself that I thought binders were needed and I missed the deadline by 2 minutes because of it.