sort by Rank | Alpha
| Possible Meanings | Rank |
| Incorporated or Referenced | **** |
| Institute of Religious Formation | **** |
| International Riesling Foundation | **** |
| Initial Request Form | **** |
| Incentive Research Foundation | **** |
| Independent Research Facility | **** |
| International Research Fellowships | **** |
| Inpatient Rehabilitation Facilities | **** |
| Internal Research Fund | *** |
| International Research Fund | *** |
| Internal Rear Focus | *** |
| Inpatient Rehab Facility | *** |
| Instrument Reflexion Filter | *** |
| Interferon Regulatory Factors | *** |
| Inherited Rights Filters | *** |
| Inrad Roofing Filter | *** |
| International River Foundation | *** |
| inheritance rights filter | *** |
| International Rangers Federation | *** |
| Impulse Response Functions | *** |
| intermediate routing function | *** |
| International Religious Foundation | *** |
| Inter Regional Flow | *** |
| Indiana Renewable Fuels | *** |
| Immediate Ready Force | *** |
| Independent Reconnaissance Flight | *** |
| International Rugby Federation | *** |
| Inter Religious Federation | *** |
| Islamic Relief Foundation | *** |
| Immunity Resource Foundation | *** |
| Internal Rear Focusing | *** |
| Insurance Reporting Foundation | *** |
| Immature Reticulocyte Fraction | *** |
| International Reining Festival | *** |
| India Retail Forum | *** |
| IFN regulating factor | ** |
| IFN response factor | ** |
| IFN-regulatory factor | ** |
| immature RET fractions | ** |
| immediate release formulation | ** |
| impaired renal function | ** |
| Improved Readability Form | ** |
| inactive rheumatic fever | ** |
| incomplete root formation | ** |
| individual radiographic features | ** |
| individual-radiographic-features | ** |
| instantaneous respiratory frequency | ** |
| insulin-related factor | ** |
| interferon regulatory factor | ** |
| interferon regulatory factors | ** |
| interferon regulator factor | ** |
| interferon regulatory factory | ** |
| interferon reguratory factor | ** |
| interferon-related factor | ** |
| interferon-responsive factor | ** |
| internal rigid fixation | ** |
| intrapelvic radiation fibrosis | ** |
| intraventricular relaxation flow | ** |
| intrinsic renal failure | ** |
| iron regulating factor | ** |
| Iron regulatory factor | ** |
| iron-regulatory factor | ** |
| Isovolumic relaxation flow | ** |
| Injuries and Fatalities | ** |
| Information Request Failure | ** |
| Immediate Response Facility | ** |
| inhibitory surrounding field | ** |
| interferon regulatory factor family | ** |
| interferon regulatory transcription factors | ** |
| inverted regimen of feeding | ** |
| Island Resource Foundation | ** |
| IFN Regulatory Factors | ** |
| Isaac Royal Farm | ** |
| Islington Refugee Forum | ** |
| immunoreactive nerve fibers | ** |
| Indigenous Researchers Forum | ** |
| Industrial Relations Forum | ** |
| IP Routing Foundations | ** |
| Industrial Research Fellowships | ** |
| Instantaneous Radiative Flux | ** |
| Inertial Reference Frame | ** |
| International Research Fellowship | ** |
| International Ringo Federation | ** |
| Islamic Revolutionary Front | ** |
| Input Register Full | ** |
| Indigenous Research Fellowship | ** |
| Industrial Research Foundation | ** |
| Instructional Resource Fee | ** |
| Intelligent Resilient Framework | ** |
| International Retail Federation | ** |
| Incident Reporting Form | ** |
| Indigenous Researcher Fellowship | ** |
| Internet Racing Friends | ** |
| Item Response Functions | ** |
| Interferon Regulatory Factor1 | ** |
| Invoice Review Form | ** |
| Interim Response Fund | ** |
| International Rosacea Foundation | ** |
| Inverted Repeats Finder | ** |
| Investigation Revolving Fund | ** |
| Indonesian Relief Fund | ** |
| Installation Response Force | ** |
| Isolate Record Forms | ** |
| Individual Reimbursement Fund | ** |
| Instituto Roberto Franco | ** |
| Instructional Reform Facilitators | ** |
| Intake Retention Fraction | ** |
| Impulse Response Filter | * |
| Instrument Response Functions | * |
| Intake Retention Function | * |
| International Revolutionary Front | * |
| Inherited Rights and Filters | * |
| Integrated Regional Forum | * |
| Initiation Response and Feedback | * |
| Instructions for FIM | * |
| Integrated Resources Framework | * |
| Internal Rotation in Flexion | * |
| Indian Religious Freedom | * |
| Initial Registration Fee | * |
| Interferon Response Factors | * |
| Interger Register File | * |
| International Relief and Friendship | * |
| International Rhinos Foundation | * |
| Irish Research Fund | * |
| Indian Republican Front | * |
| Individual Risk Factors | * |
| Industry Reference File | * |
| Internal Raster File | * |
| Internal Raster Format | * |
| Internal Relay Fault | * |
| International Reformed Fellowship | * |
| Inventory Record File | * |
| Investment in Reinvention Fund | * |
| Imagery Readiness Facility | * |
| Inspection Request Form | * |
| Instaneous Radiant Flux | * |
| Illinois Rules for Floodways | * |
| Image Retrieval Facility | * |
| Images from the Roswell Film | * |
| Independent Rugby Forum | * |
| Index Running Fitness | * |
| Individualist Research Foundation | * |
| Information Research Facility | * |
| Information Resource Facility | * |
| Investigative Research Field | * |