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Acronyms for HEF

Home Education Foundation
High Elf (Everquest)
High-Energy Fuel
High Efficiency Filter
Hispana Esperanto-Asocio
Hazardous Equipment or Facilities
Heredes Eius Fecerunt (Latin: His/Her Heirs Built, epigraphy)
Houston Environmental Foresight
Hamster Embryo Fibroblast

*courtesy: http://www.acronymfinder.com/hef.html