Abbreviations beginning with i

I/VSInterpretation/Visitor Services (US National Park Service)
Governmental

I/YInterest per Year
Business

I:EInspiration to Expiration (ratio; also seen as I/E)
Academic & Science

I:GInsulin:glucose (ratio)
Academic & Science

I:TImmature/Total Neutrophil (perinatal medicine)
Academic & Science

I\OInput\Output
Computing

I+DInvestigación y Desarrollo (Spanish: Research and Development)
Miscellaneous

I=E/RElectrical measured current flow
Academic & Science » Electronics

I=PATImpact = Population x Affluence x Technology (environmental impact)
Academic & Science

I03Information Object Oriented Obsidian 3
Business » International Business

I0MI Owe Money
Internet » Chat

I1Imperfect 1 (diamonds)
Miscellaneous

I11international 11
International

I12Inspection 12 (band)
Miscellaneous

I-131Radioactive Iodine
Medical » Oncology

I18NInternationalization (I followed by 18 letters, followed by N; user interface localization)
Academic & Science

I18NInternationalization
Computing » IT