SIP, standing for Standard Interchange Protocol, was developed by the 3M corporation to be a common protocol for data transfer between ILS' (referred to in SIP as an ACS, or Automated Circulation System) and a third party device. Originally, the protocol was developed for use with 3M SelfCheck (often abbreviated SC, not to be confused with Staff Client) systems, but has since expanded to other companies and devices. It is now common to find SIP in use in several other vendors' SelfCheck systems, as well as other non-SelfCheck devices. Some examples include: