Information security risks threaten the ability of organizations of reaching their operational and strategic goals. Increasing diversification of the information security landscapes makes addressing all risks a challenging task. Information security standards have positioned themselves as generic solutions to tackle a broad range of risks and try to guide security managers in their endeav ors. However, it is not evident if such standards have the required holis tic approach to be a solid foundation. In this paper a metamodel of the ISO 27001 security standard explicating its core concepts is presented. We then compare the constructed metamodel with various information security ontolo gies and analyze for comprehensiveness. We conclude with a discussion of core concepts in the information security domain.