Architectural Dictionary – R A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Rainwater Down Pipe (RWDP) Reconstruction (RECON) Rectangular Hollow Section (RHS) Reflected Ceiling Plan (RCP) Registered Inspector (RI) Reinforced Concrete (RC) Riser (R) Road Level (RL) Road Line Plan (RLP)