Sciences

• PH (complexity), the union of all people classes in the polynomial hierarchy in computational complexity theory
• Phenyl group
  Phenyl group
  In organic chemistry, the phenyl group or phenyl ring is a cyclic group of atoms with the formula C6H5. Phenyl groups are closely related to benzene. Phenyl groups have six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the...
  
  , either -Ph or Φ, highly-stable and aromatic hydrocarbon unit found in many organic compounds
• phot
  Phot
  A phot is a photometric unit of illuminance, or luminous flux through an area. It is not an SI unit, but rather is associated with the older centimetre gram second system of units...
  
  , or ph, a measurement of illuminance (photometry)
• pico- henry (unit), an SI Unit of electrical inductance
• Pleckstrin homology domain, a part of many proteins which bind phosphoinositides with high affinity
• Pulmonary hypertension
  Pulmonary hypertension
  In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
  
  , a medical condition
• Soil pH
  Soil pH
  The soil pH is a measure of the acidity or basicity in soils. pH is defined as the negative logarithm of the activity of hydrogen ions in solution. It ranges from 0 to 14, with 7 being neutral. A pH below 7 is acidic and above 7 is basic. Soil pH is considered a master variable in soils as it...
  
   is a measure of soil acidity or soil alkalinity

Aviation

• PH, Aircraft registration
  Aircraft registration
  An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...
  
   prefix for the Netherlands
• Polynesian Airlines
  Polynesian Airlines
  Polynesian Airlines is the national airline of Samoa and has its headquarters in the Samoa National Provident Fund Building in the capital, Apia. It formerly flew all over the Pacific but with the establishment of Polynesian Blue by the government and Virgin Blue , Polynesian Airlines has...
  
  ' IATA airline designator
• Transavia.com Denmark
  Transavia.com Denmark
  Transavia Denmark ApS, also known as Transavia.com Denmark or Transavia Denmark and trading as transavia.com, was a Danish based low-cost airline operating as a subsidiary of Transavia.com group. Its main base was at Copenhagen Airport. Transavia Denmark chiefly operated scheduled and charter...
  
  's IATA airline designator

Other uses

• PH, the Philippines
  Philippines
  The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
  
  ' ISO country code
  • .ph
    .ph
    -Introduction:The official domain registry of the .ph domain is dotPH Domains Inc. dotPH holds and maintains the database of PH domain names, specifically .ph, .com.ph, .net.ph, .org.ph, and .i.ph...
    
    , the Philippines' Internet country code top-level domain
• pʰ, a phoneme
• Ph (digraph), a common digraph that represents the phoneme /f/ (voiceless labiodental fricative) in phonetics
• Ph protocol, an early web database search for CCSO Nameserver
  CCSO Nameserver
  A CCSO name-server or Ph protocol was an early form of database search on the web. In its most common form it was used to look up information such as phone numbers and e-mail addresses. Today this service has been largely replaced by LDAP. It was used mainly in the early-to-middle 1990s...
  
   described by RFC 2378
• Poul Henningsen
  Poul Henningsen
  Poul Henningsen , Danish author, architect and critic, was one of the leading figures of the cultural life of Denmark between the World Wars. In Denmark, he is often referred to as PH.-Early life and education:...
  
   (1894–1967) Danish writer and designer referred to as PH in Denmark
• on maps, an abbreviation for a Public house
  Public house
  A public house, informally known as a pub, is a drinking establishment fundamental to the culture of Britain, Ireland, Australia and New Zealand. There are approximately 53,500 public houses in the United Kingdom. This number has been declining every year, so that nearly half of the smaller...