The document outlines principles for perimeter play regarding guarding, screening, and contact situations. It describes the 4 situations for guarding an opponent and establishes that a defender must obtain a legal guarding position first before contact can be considered. Screening principles also establish 4 situations and state that screens must be set in a stationary position without intent to widen the body. The overall focus is on officiating based on established principles to determine legal positions and avoid advantages through illegal contact.