Proportional Representation summary and related information.

Protestant Reformation

Portuguese Republic

PR commonly stands for Public relations. PR may also stand for (alphabetically):

denoted Pr(...), the probability of an event in probability theory

Peer review

PageRank is a link analysis algorithm that assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of "measuring" its relative importance within the set. The algorithm may be applied...

Permanent Revolution

Proportional representation, a class of voting systems used in most of the world, including Germany, Italy, New Zealand, and some elections in Australia

Progesterone receptor, a protein

Partial response, in oncology

Pakistan Railways

Pershing Rifles

Press release

Perpendicular recording

Permanent Residency

Performance rating

Party of Regions

Photorefractive summary and related information.

personal record, in competitive events such as cross country running or track and field

Philippine Airlines, IATA airline designator

Planetary Radio, the radio show about space exploration by The Planetary Society

Poste Restante (abbrev. GD), also known as General Delivery, a service where the post office holds mail until the recipient calls for it.

Posting reference, in the ledger in accounting

PR (complexity), a complexity class

Prandtl number, in physics and engineering

Praseodymium, chemical element number 59 (abbreviated "Pr")

Premiere, Adobe software which uses "Pr" as its icon abbreviation.

Project Reality, a mod for Battlefield 2

Propyl radicals, in organic chemistry

Punt returner, a position in American football

Paraná (state), Brazil. (ISO 3166-2:BR)

Parma (province) Italy. (ISO 3166-2:IT)

Puerto Rico (territory), USA. (ISO 3166)