# PL

PL, P.L., Pl, or .pl may refer to:

## Businesses and organizations
### Government and political

* Partit Laburista, a Maltese political party
* Liberal Party (Brazil, 2006), a Brazilian political party
* Liberal Party (Moldova), a Moldovan political party
* Liberal Party (Rwanda), a Rwandan political party
* Parlamentarische Linke, a parliamentary caucus in Germany
* Patriotic League (Bosnia and Herzegovina) (Bosnian: Patriotska Liga), a military organisation of the Republic of Bosnia and Herzegovina
* Philippine Legislature, a legislature that existed in the Philippines from 1907 to 1935
* Progressive Labor Party (United States), a United States communist party

### Sports leagues

* Palestine League, the top Palestinian football league
* Premier League, the top English football league
* Pacific League, one of the two leagues in Japan's Nippon Professional Baseball
* Pioneer Baseball League, a Rookie league in American Minor League Baseball
* Pioneer Football League, NCAA FCS conference
* Priaulx League, senior football league on the island of Guernsey

### Other businesses and organizations

* Airstars Airways (IATA airline designator PL, 2000–2011)
* Aeroperú (IATA airline designator PL, 1973–1999)
* Papillion-La Vista Senior High School in Papillion, Nebraska, USA
* Public library, a library maintained by government for public use
* Professional Limited Liability Company, a limited liability company organized for the purpose of providing professional services

## Places

* PL postcode area, UK, a group of postcode districts in England
* Poland (ISO 3166-1 country code)

## Religion

* PL Kyodan, a religious movement founded in Japan in the early 20th century
* Patrologia Latina, a collection of Catholic writings published by Jacques-Paul Migne between 1841 and 1855

## Science, technology, and mathematics
### Chemistry

* Pyridoxal, one form of vitamin B6
* Pulchellidin (Pl), an anthocyanidin
* Phospholipid, a class of lipids that are a major component of all cell membranes

### Computing and telecommunications
#### File formats

* .pl, common filename suffix for Perl scripts
* .pl, common filename suffix for Prolog programs
* .pl, common filename suffix for TeX font property lists

#### Programming

* Programming language
** PL/C, an instructional dialect of the PL/I computer programming language, developed at Cornell University in the 1970s
** PL/I, a computer programming language developed in the 1960s
** PL/SQL, Oracle's procedural language extension (inception in 1995)
** PL/pgSQL, PostgreSQL's procedural language extension (inception 1998)

#### Telecommunication and networking

* .pl, country code top-level domain for Poland
* PL tone, a kind of squelching of an audio signal
* Packet loss, one of the three main error types encountered in digital communications
* Path loss, in telecommunication engineering
* Presentation layer, one of the seven layers in the OSI model of computer networking
* Digital Private Line, another form of tone squelching

### Mathematics

* Piecewise linear (disambiguation), in mathematics
* Propositional logic, a system of evaluating truth-based propositions in terms of binary logic
* PL (complexity), in complexity theory

### Other uses in science and technology

* Ice pellets (METAR weather code PL), a form of precipitation
* Picolitre (pL), and petaliter (PL), units of volume
* Pluto, a dwarf planet
* Photoluminescence, the re-emission of photons from a surface following exposure
* Pierre Levasseur (aircraft builder), a French aircraft designer
* Plastic limit, in geotechnical engineering
* PL / Positive Lock, a lens mount used on Arri cameras and lenses
* pl., abbreviation for printing plates, often indicating the number of plate-based illustrations in a book
* Adobe Prelude, an Adobe software

## Other uses

* Platoon leader, in the US Army
* Plural, in grammar
* Polish language (ISO 639-1 code "pl")
* Political Liberalism, a 1993 book by the American philosopher John Rawls
* Private label, an arrangement between companies regarding the exclusive sale of goods
* Public law
* Public liability