What does RI stand for?

Chicago, Rock Island & Pacific Railroad Co. (MHDB)

Eastern Airlines - ICAO designator (AD)

Indonesia - IYRU nationality code (IYR)

Input Resistor (STED)

Member of the Royal Institute of Painters in Water Colours - British

Morrison Restaurants, Inc. - NYSE symbol (SPSG)

Morrone - NCIC firearms make code (NCIC)

Racial Immunity (UWER)

RADAR Indication (UWER)

RADAR Input (UWER)

RADAR Intercept (IAA)

RADAR Interference (LAIN)

Radar Interferometry (SAUS)

RADAR Interrogation (UWER)

Radiation Indicator - Nuclear energy (NRCH)

Radiation Intensity (AABC)

Radicalist International - Defunct (EA)

Radice Corp. - NYSE symbol (COMM)

Radioactive Isotope - Medicine (EDAA)

Radiographic Inspection (UWER)

Radiographic Intensifier (SAUS)

Radioimmunology (DB)

Radio Industries (SAUS)

Radio Industry - Telecommunications (IAA)

Radio Inertial (MCD)

Radio Influence

Radio Inspector

Radio Intelligence (SAUS)

Radio Interface (SAUS)

Radio Interference (MCD)

Radiointerferometer (SAUS)

Radio Iran (SAUS)

Radioisotope

Radix Institute (EA)

Rampart Institute (EA)

Random Interlace - Television

Random Interval (AEBS)

Range Instrumentation (MCD)

Range of first Intercept (SAUS)

Ranger Instructor - Army

REACT International (EA)

Reactor Island - Nuclear energy (NRCH)

Readers International - Subscription book club - British

Read-In (DEN)

Read Instruction (SAUS)

Real Image (SAUS)

Reallocation Inventory (AFIT)

Receiver Interface

Receiving Inspection (AAG)

Recession Index (STED)

Recipe Index - A publication

Recombinant Inbred - Genetics

Reconnaissance Inspection - Military (GFGA)

Recordable Injury (SAUS)

Record Input (SAUS)

Recovery, Inc.

Recruit Induction - Military

Recruit Instruction - Navy

Rectifier Instrument (SAUS)

Recurrent Intussusception

Redheads International (EA)

Reduction Index (SAUS)

Re-examine/Re-inspect (SPVS)

Reference Implementation (VLIE)

Referential Integrity - Computer science

Reflective Insulation - Technical drawings

Refraction Intercept (SAUS)

Refractive Index

Refractories Institute (SAUS)

Refugees International (EA)

Regenerative Index (STED)

Regimental Institute - British military (DMA)

Regina Imperatrix - Queen Empress - Latin

Regional Ileitis - Medicine

Register Immediate (VLIE)

Registro Italiano - Italian ship classification society (DS)

Regular Insulin - Pharmacology (DAVI)

Regurgitant Index (SAUS)

Rehabilitation International (EA)

Reimplantation - Dentistry

Reinitiate (SAA)

Reinstated - Motor vehicle violation code used in state of Maryland (MVRD)

Reinsurance (ADA)

Reinsured (SAUS)

Reissue - of a book or periodical - Publishing

Relative Intensity

Relaxation Instruction - Psychology

Release-Inhibiting (SAUS)

Release-Inhibiting Factor - Endocrinology (MAE)

Release Inhibition (STED)

Reliability Improvement (SAUS)

Reliability Index

Religious Instruction (ADA)

Remedial Investigation - Environmental Protection Agency (DOMA)

Remission Induction - Oncology

Renal Insufficiency - Medicine (STED)

Rename Inhibit (VLIE)

Repeat Indication - Telecommunications (TEL)

Repetitive Instruction (SAUS)

Replacable Item (SAUS)

Replaceable Item

Replicative Intermediate - Medicine (MAE)

Report of Investigation

Reports of Investigation (SAUS)

Reproducibility Index (SAUS)

Reproductive Immunologist (SAUS)

Republic Indonesia (SAUS)

Republic of India (SAUS)

Repulsion Induction - Motor

Request for Information (MCD)

Require Identification

Rescue, Inc. (EA)

Research Institute - Fort Belvoir, VA - United States Army Engineer Topographic Laboratories (GRD)

Research International - Commercial firm

Residual Income

Resistance Index

Resistance Inductance (IEEE)

Resistance International (EA)

Resolve, Inc. (EA)

Resonance Integral - Nuclear energy (NRCH)

Respiratory Illness - Medicine

Respiratory Index (STED)

Respiratory Infection (SAUS)

Results International, Inc. - Commercial firm

Retention Index

Reticulocyte Index (STED)

Retirement Income

Retreats International (EA)

Retroactive Inhibition - Psychology

Retroactive Interference (STED)

Retroaktive Inhibition (SAUS)

Retrograde Inversion (SAUS)

Return Instruction (SAUS)

Reunite, Inc. (EA)

Reverberation Index

Reverse Image (SAUS)

RHEMA - Restoring Hope through Educational and Medical Aid International (EA)

Rhode Island - Postal code

Rhode Island Supreme Court Reports - A publication (ILCA)

Ribonuclease Inhibitor

Ribosomal - Protein - Cytology

Rice - Soil biology - Human-introduced crops (QSUL)

Rice Institute (SAUS)

Rideability Index (SAUS)

Rifle, Semiautomatic - NCIC gun type code (NCIC)

Right Iliac - Crest - Anatomy (DAVI)

Right In (VLIE)

Rigorous Imprisonment - British military (DMA)

Ring In (SAUS)

Ring Index - of chemical compounds - A publication

Ring Indicate (SAUS)

Ring Indication (VLIE)

Ring Indicator - MODEM

Ringing - Modem status information light - Computer science (IGQR)

Rio-Sul, Servicos Aereos Regionais SA - Brazil - ICAO designator (ICDA)

Risk Index (SAUS)

Risk Investigation (UWER)

Robotics Institute (SAUS)

Robotics International (SAUS)

Robotics International Association of the Society of Manufacturing Engineers (BTTJ)

Rock Island Lines - Railroad

Rockwell International Corp. (MCD)

Rockwell International Corp., Pittsburgh (SAUS)

Rodale Institute (EA)

Rodale International (SAUS)

Rodale Intstitute (EA)

Rolf Institute (EA)

Ron Iberg - Air show performer (ASPC)

Room Index (PDAA)

Roses, Inc. (NTPA)

Rosette Inhibition (STED)

Rotary International (EA)

Rotating Inventory (SAUS)

Routing Identifier - or Indicator (AFM)

Routing Indication (SAUS)

Routing Indicator

Routing Information (SAUS)

Royal Institute (SAUS)

Royal Institute of Painters in Watercolours - British (WA)

Royal Institute of Painters in Water-Colours, London - 1831 (NGC)

Royal Institution - British

Royal Irish - Military unit - British

Rubber-Insulated (SAUS)

Rubber Insulation - Technical drawings

Ruby Tuesday - NYSE symbol - Formerly, Morrison Restaurants (SPSG)

Ruby Tuesday, Inc. - NYSE symbol (SAG)

Rule Interpretation

Rulers of India - A publication

Runaway Inflation (MHDB)

Rust Inhibitor - Fuels and lubricants

Rutherford Institute (EA)

Remedial Investigation - Office of Environmental Management, Department of Energy (DEEM)

Ricardus Anglicus - Deceased, 1242 - Authority cited in pre-1607 legal work (DSA)

Richardson Number - Physics

Input Resistance (IDOE)