RR

other meanings

Military

Ready and Resilient (R2) is the Army's strategy for strengthening individual and unit Personal Readiness and fostering a culture of trust. … Every Soldier is a valued member of the Army team and is critical to readiness and mission accomplishment.

Science

R2: Risk of explosion by shock, friction, fire or other sources of ignition, a risk phrase in chemistry

R2[1] is a 1950s- and 1970s-era channel-associated-signalling signalling protocol used outside of the former Bell System[where?] to convey information along a telephone trunk between two telephone switches in order to establish a single telephone call along that trunk.

R2 is the name given to two broad protocol groups: R2 line signalling and R2 register signalling