PDF (disambiguation)

PDF commonly refers to the Portable Document Format in computing.

Other uses could also mean:

 In education 
 Postdoctoral fellow

 In fiction 
 Planetary Defence Force in the Warhammer 40,000 universe

 In the military 
 Panama Defense Forces
 P.D.F. (upper case) is an abbreviation of "Permanent Defence Forces" - the standing branches of the Irish Defence Forces
 People's Defence Force - the army of Grenada before the US led invasion in 1983.

 In science 
 Atomic pair distribution function (Physics)
 Parkinson's Disease Foundation (http://www.pdf.org) (Medicine)
 Parton Distribution Functions (Physics)
 Planar deformation features (Geology)
 Polypeptide Deformylase (Chemistry)
 Powder Diffraction File (Physics)
 pdf and p.d.f. (lower case) can refer to "probability density function" (Mathematics, statistics and probability)
 PDF and P.D.F. (upper case) can refer to "probability distribution function" (Mathematics, statistics and probability)

 In software 
 Package Definition File (Microsoft Systems Management Server)
 Portable Document Format
 Printer Description File, in earlier editions of Quark Xpress page layout software.

 Additional uses 
 KPDF-CA, a television station in Phoenix, Arizona
 PDF417, a 2D barcode - PDF means Portable Data File
 PDF Solutions, a listed company headquartered in San Jose, California
 Peace Development Fund, a non-profit public foundation based in Amherst, Massachusetts
 Peak draw force in a Compound bow in Archery 
 Playa del Fuego, a Delaware art festival inspired by the annual Nevada Burning Man festival
 An abbreviation of Pretty Damned Funny