Dictionary of Nomenclature of Celestial Objects

Pi Write:

Details on Acronym:   Pi
  
(Cyrillic letter for Parenago) <<Parenago NNNNA>>
Object:*  (SIMBAD class: Star)
Note:Pi = $Pi.
in source:NAME Orion Nebula
Ref:=1954TrSht..25....1P
byPARENAGO P.P.
 Trudy Gosud. Astron. Inst. Shternberga, 25, 1-None (1954)
  Catalogue of stars in the area of the Orion Nebula.
o<Parenago NNNN> (Nos 1-2982)

*****

Avoid the usage of Pi , prefer Parenago