I believe it may stand for electronic parking brake.
It seems they eliminated the rear drum brakes and utilize electronic system to squeeze the caliper for the emergency brake.
USA 2024 Ranger Raptor
Ford CoPilot-360 ™ features* Lane Centering, Auto High Beams, BLIS® (Blind Spot Information System) with Cross-Traffic Alert and Trailer Coverage, Pre-Collision Assist with Automatic Emergency Braking (AEB), Rearview Camera, Intersection Assist, Active Park Assist 2.0...