IEC 61511-2:2016 is available as <a href="https://webstore.iec.ch/publication/25521">IEC 61511-2:2016 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 61511-2:2016 provides guidance on the specification, design, installation, operation and maintenance of SIFs and related SIS as defined in IEC 61511-1:2016. This second edition cancels and replaces the first edition published in 2003. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: guidance examples based on all phases of the safety life cycle provided based on usage experience with IEC61511 1st edition; annexes replaced to address transition from software to application programming.