Harmonized Microdata in XML Format This section contains microdata files for all Forms 990-PF sampled for the annual SOI studies of private foundations. The data from each of the annual studies are included in a single, "harmonized" dataset, with standardized element names and codes based on the form revision of the latest available Tax Year. The SOI sample includes returns filed by private foundations, exempt under Internal Revenue Code section 501(c)(3), and section 4947(a)(1) nonexempt charitable trusts. The stratified random samples are based on asset size and represent approximately 10 percent of Forms 990-PF filed; sampling rates of 100 percent are applied to large-asset classes. Microdata records contain most financial information from Forms 990-PF, as well as weights (to estimate the population), for each organization. Main Data Files (from Form 990-PF) 1985-2010ZIP 2011-2018ZIP Compensation Data Files (from Form 990-PF, Part VIII) 1993-2010ZIP 2011-2018ZIP Marked up Form 990-PFPDF: 2018 Form 990-PF, marked with the Name / Element Code. Form 990-PF InstructionsPDF: 2018 Form 990-PF Filing Instructions. Unrelated Business Activity CodesPDF: 2018 SOI Form 990-PF study, business code reference list. Exclusion Code ReferencePDF: 2018 SOI Form 990-PF study, exclusion code reference list for Part XVI-A, Analysis of Income-Producing Activities.