What does RAB have to do with the horcruxes?

Answer:
RAB is Regulus Arcturus Black. He's younger brother of Sirius Black. He stole The Slytherin's Locket and ordered Kreacher to destroy it who failed miserably. Then locket was stolen by Mundungus and further taken away by Umbridge. Finally Ron Weasley was able to destroy the horcrux.
First answer by Vivek Ramasha. Last edit by Vivek Ramasha. Contributor trust: 3 [recommend contributor recommended]. Question popularity: 0 [recommend question].