This part of This part of IEC 62443 , which is a Technical Report, describes requirements for asset owners and industrial automation and control system (IACS) product suppliers that have established and are now maintaining an IACS patch management program. This Technical Report recommends a defined format for the distribution of information about security patches from asset owners to IACS product suppliers, a definition of some of the activities associated with the development of the patch information by IACS product suppliers and deployment and installation of the patches by asset owners. The exchange format and activities are defined for use in security related patches; however, it may also be applicable for non-security related patches or updates. The Technical Report does not differentiate between patches made available for the operating systems (OSs), applications or devices. It does not differentiate between the product suppliers that supply the infrastructure components or the IACS applications; it provides guidance for all patches applicable to the IACS. Additionally, the type of patch can be for the resolution of bugs, reliability issues, operability issues or security vulnerabilities. NOTE1 This Technical Report does not provide guidance on the ethics and approaches for the discovery and disclosure of security vulnerabilities affecting IACS. This is a general issue outside the scope of this report. NOTE2 This Technical Report does not provide guidance on the mitigation of vulnerabilities in the period between when the vulnerability is discovered and the date that the patch resolving the vulnerability is created. For guidance on multiple countermeasures to mitigate security risks as part of an IACS security management system (IACS-SMS), refer to, AnnexesB.4.5, B.4.6 and B.8.5 in this Technical Report and other documents in the IEC62443 series.