What does I stand for?

Airborne Intercept (SAUS)

Air Force Training Category [No training]

Angle of Incidence

Carlo Erba [Italy] [Research code symbol]

Current [Communications term] (DCT)

Electric Current [Symbol] [IUPAC]

Electric Flow in Amperes (NTIO)

Fighter [Russian aircraft symbol]

First Interstate Bancorp. [NYSE symbol] (SPSG)

I-Band (MELL)

I-Beam [Structural metal shape]

Ibuprofen [A drug]

Ice (ADWA)

Iconoscope (IAA)

Id [That] [Latin] (GPO)

Idaho

Identification

Idus [The Ides] [Latin]

Ihr [Your] [German]

Illinois State Library, Springfield, IL [Library symbol] [Library of Congress] (LCLS)

Illite [A mineral]

Illuminated (WDMC)

Illumination (IAA)

Illuminous Intensity (SAUS)

Image [File] [Computer science] [Telecommunications]

Imaginary (IAA)

Imaginary Number (NTIO)

Immediate [Emergency Management] (EMA)

Imperator [or Imperatrix] [Emperor or Empress] [Latin]

Imperial

Imperial Paper (DGA)

Implantation (MELL)

Implicit

Impression (DAVI)

Inactive (STED)

Inboard (DS)

Incendiary [Bomb]

Inch (ODA)

Incident Ray (IDOE)

Incisal [Dentistry] (DAVI)

Incision (MELL)

Incisor (Permanent) [Dentistry]

Inclination

Income

Incompatible

Incomplete

Incontinent [Medicine]

Increased (STED)

Incumbent (ROG)

Independence (IDYL)

Independent

Independent Gasoline Marketers Council (EA)

Independent Motion Picture Producers Association (EA)

Independent School [British]

Index

Index Number (DIPS)

India [Phonetic alphabet] [International] (DSUE)

Indian (WGA)

India National Congress [Political party] (PSAP)

Indicated [or Indicative]

Indicated Horsepower

Indicated Main Engine

Indicator

Induction

Industrial

Industrial Jacks Product Section of the Material Handling Institute (EA)

Industrial Premises [Public-performance tariff] [British]

Industrial Training School [British] (ROG)

Industrial Vegetation Management Association (EA)

Inertia (AAG)

Inertias (SAUS)

Infantry

Infield

Inflection [Linguistics] (IEL)

Informal [FCC special temporary authorization] (NTCM)

Information [Computer science]

Information Management and Processing Association (EA)

Infra (IAA)

Inhalation (DMAA)

Inhibition (STED)

Inhibitor (DMAA)

Inhibitory

Initial

Ink [Phonetic alphabet] [Royal Navy] [World War I] [Pre-World War II] (DSUE)

Inlet [Rotary piston meter]

Inner

Inosine [One-letter symbol; see Ino]

Inphase (SAUS)

Input

Inside

Inside Edge [Skating]

Insoluble

Inspection (ACAE)

Inspector

Inspiration (STED)

Inspired [Medicine] (DAVI)

Instantaneous

Instantaneous Current (IDOE)

Instantaneous Value (IDOE)

Institute [or Institution]

Institutional (WDMC)

Instruction

Instructional Program (NTCM)

Instructor (WDAA)

Instrumental [or Instrumentation]

Instrument Correction

Insulated (DS)

Insulated Tank [Liquid gas carriers]

Insulin (MELL)

Insurance Economics Society of America (EA)

Intact (DAVI)

Intake (AAMN)

Integer (IAA)

Integral (IAA)

Intelligence

Intensity

Intensity of Magnetism (STED)

Interbank [Credit cards]

Intercalary (STED)

Intercept-Aerial [Missile mission symbol]

Interceptor

Interchangeability (AAG)

Intercooled [Automotive engineering]

Interest [Economics]

Interference [Broadcasting]

Interim [FCC] (NTCM)

Interlocked Metallic Armor [Technical drawings]

Intermediate [Vessel load line mark]

Intermediate Slope [Skiing]

Intermittent (DMAA)

Intermittent Operation during the Time Indicated [Broadcasting]

Intern

Internal

Internalized [Linguistics] (IEL)

Internal Medicine (AAMN)

International

International Association of Intermodal Equipment Surveyors (EA)

International Conference Industry Association (EA)

International Organization of Women in Telecommunications (EA)

International Photo Optical Show Association (EA)

International Quick Printing Foundation (EA)

International Royal Enterprises (EA)

Internist [Medicine]

Interphone (IAA)

Interphone and PA [Communications term] (DCT)

Interpole (IAA)

Interpreter

Interrupt [Computer science] [Telecommunications]

Interstate [Highways]

Intestine

Intransitive

Intraocular Lens Manufacturers Association (EA)

Intrapictures [Electronics]

Intrinsic Semiconductor (IDOE)

Intrinsic-Type, Semiconductor Material

Introduced [Ecology]

Introversion

Invasive

Inventory

Inverted Sentence [Used in correcting manuscripts, etc.]

Inverter

Investment

Iodine [Chemical element]

Ionic Strength

Ionization Potential (ODA)

Iota [Ninth letter of the Greek alphabet] (DAVI)

Iraqi

Ireland

Iris (MELL)

Irnerius [Flourished, 1113-18] [Authority cited in pre-1607 legal work] (DSA)

Iron [Symbol is Fe] [Chemical element] (ROG)

Irradiated (NASA)

Irregular (ROG)

Irrigation [Medicine]

Ischium (MELL)

Island [Maps and charts]

Isle

Isoflurane [An anesthetic]

Isoleucine [One-letter symbol; see Ile] [An amino acid]

Isometric [Botany]

Isopin (WDAA)

Isoproterenol [An adrenergic]

Isotope (DMAA)

Isotropic Phase (SAUS)

Israeli

Issue (ROG)

Italy [IYRU nationality code]

ITEL Corp. (SAUO)

Item [Phonetic alphabet] [World War II] (DSUE)

Luminous Intensity [Symbol] [IUPAC]

Minneapolis [Branch in the Federal Reserve regional banking system] (BARN)

Moment of Inertia [Symbol] [IUPAC]

One [Roman numeral]

Paid This Year, Dividend Omitted, Deferred, or No Action Taken at Last Dividend Meeting [Investment term] (DFIT)

Radiant Intensity [Symbol] [IUPAC]

Registro Italiano [Shipping] (ROG)

Requires a Doctor [Search and rescue symbol that can be stamped in sand or snow]

Unit Matrix (ODA)

Class Interval [Statistics]

Ideal [Medicine] (QSUL)

Imaginary Number (SHCU)

Imaginary Unit (WGA)

Immortalis [Immortal] [Latin] (GPO)

Imperial Savings (SAUS)

Improbatur [Latin]

Impurity [Medicine] (EDAA)

Inactive [Chemistry]

incisor (SAUS)

Incisor (Deciduous) [Dentistry]

Independent Pump [Liquid gas carriers]

Indian Ocean [MARC geographic area code] [Library of Congress] (LCCP)

Ink (VRA)

Interest (SHCU)

I-Orbital (MEC)

Isochromosome (MAE)

Isopentenyl [As substituent on nucleoside] [Biochemistry]

Tourist Information [Traffic sign] [British]