In Europe Passenger Name Record (PNR) data exchange is regulated to support prevention, detection, investigation and prosecution of terrorist offences and serious crime.  Annex 2 of the recent  COMMISSION IMPLEMENTING DECISION (EU) 2017/759 of 28 April 2017, which specifies the common protocols and data formats to be used by air carriers when transferring PNR data to Passenger Information Units,  mandates the OASIS AS4 standard as one of three allowed protocols for transmission protocols for the transfer of data.