This part of ISO/IEC 15026 specifies the concept of integrity levels with corresponding integrity level requirements that are required to be met in order to show the achievement of the integrity level. It places requirements on and recommends methods for defining and using integrity levels and their corresponding integrity level requirements. It covers systems@ software products@ and their elements@ as well as relevant external dependences. This part of ISO/IEC 15026 is applicable to systems and software and is intended for use by the following: a)definers of integrity levels such as industry and professional organizations@ standards organizations@ and government agencies: b) users of integrity levels such as developers and maintainers@ suppliers and acquirers@ system or software users@ assessors of systems or software and administrative and technical support staff of systems and/or software products. One important use of integrity levels is by suppliers and acquirers in agreements: for example@ to aid in assuring safety@ financial@ or security characteristics of a delivered system or product. This part of ISO/IEC 15026 does not prescribe a specific set of integrity levels or their integrity level requirements. In addition@ it does not prescribe the way in which integrity level use is integrated with the overall system or software engineering life cycle processes. It does@ however@ provide an example of use of this part of ISO/IEC 15026 in Annex A.