RA Ripple Adder RA Postal Tax Stamp (Scott Catalogue prefix; philately) RA Red Armageddon (gaming clan) RA Repeat and Accumulate (type codes) RA Ready Analog RA Restricted Artistic (movie rating) RA Responsable d'Activités (French: Head of Activities) RA Reinforced Alert RA Règle Administrativ...
BRBlack Adder BRBoilermaker(USN Rating) BRBottle Rockets(band) BRBatch Reactor(chemical reactor where volume is constant and the contents are well-mixed) BRBacteriorhodopsin BRBank Roll BRBattle Rifle(gaming, Halo) BRBend Radius(cable flexibility) ...