Complex sentence: The Pirate Movement is non-governmental organization (NGO) registered on 21 September 2012, founded by majority group of Pirate Party'Core Team' members, following disagreements over support of the 2012 Belgrade Pride parade.
Split into simpler sentences: The Pirate Movement is non-governmental organization (NGO) registered on 21 September 2012, founded by majority group of Pirate Party'Core Team' members. Movement formation followed disagreement over support of the 2012 Belgrade Pride parade.