What does R.R stand for?

What does R.R mean?

RR	RailRoad Business » International Business
RR	Railroad Governmental » Transportation
RR	Research Report Academic & Science » Universities
RR	Rolls Royce Business » Firms
RR	Relative Risk Business » General
RR	Rail Road Regional » Railroads
RR	Relative Risk Governmental » FDA
RR	Response Rate Medical » Physiology
RR	Risk Reduction Academic & Science » Ocean Science
RR	Round Robin Computing » Networking
RR	Round Rock Governmental » State & Local
RR	Re Reading Community » Educational
RR	Respiratory Rate Medical » Physiology
RR	Risk Ratio Academic & Science » Mathematics
RR	Resource Record Computing » General
RR	Rapid Rise Academic & Science » Chemistry
RR	Recruitment and Retention Governmental » Military
RR	Road Racing Community » Sports
RR	Roy Rogers Community » Famous
RR	Run Run Community » Sports
RR	Rural Route Governmental » US Government
RR	Rural Route Miscellaneous » USPS
RR	Registered Representative Business » Positions
RR	Religious Right Community » Religion
RR	Removal Rate Academic & Science » Electronics