Editing PPI (section)

==Science and technology==
===Biochemistry===
* PP<sub>i</sub>, the anion P<sub>2</sub>O<sub>7</sub><sup>4−</sup>, a [[pyrophosphate]]
* [[Polyproline I helix]]
* [[Protein–protein interaction]]

===Medicine===
* [[Patient and public involvement]]
* [[Prepulse inhibition]], of a later pulse
* [[Proton-pump inhibitor]], a class of medications
* [[Psychopathic Personality Inventory]], a personality test
* [[Psychophysiological Interaction]], fMRI analysis technique

===Computing===
* [[Parallel Peripheral Interface]], of the Blackfin processor
* Programmable Peripheral Interface, [[Intel 8255]] chip
* [[Programmable Peripheral Interconnect]], in Nordic nRF microcontrollers 
* [[Pixels per inch]], of a display
* [[Stepstone|Productivity Products International]], commercializer of the [[Objective-C]] language

===Other science and technology===
* [[Gabarit passe-partout international]], in railways
* Picks per inch, a [[units of textile measurement#Picks per inch|unit of textile measurement]]
* [[Plan position indicator]], radar display
* [[Polymethylene polyphenylene isocyanate]]