IPU

IPU as an acronym stands for:

Invisible Pink Unicorn, a fictional goddess popularized on a Usenet group about atheism, and intended to satirize religious beliefs
Inter-Parliamentary Union, the world organisation of parliaments
International Postal Union, now called the Universal Postal Union, an organization that coordinates the international postal system
Interplanetary Phenomenon Unit, an informal U.S. Military group active in the 1940's and 1950s.
Image Processing Unit, the part Sony's of Emotion Engine that decodes image data.