ISO 27799:2016 gives guidelines for organizational information security standards and information security management practices including the selection, implementation and management of controls taking into consideration the organization's information security risk environment(s). It defines guidelines to support the interpretation and implementation in health informatics of ISO/IEC 27002 and is a companion to that International Standard. ISO 27799:2016 provides implementation guidance for the controls described in ISO/IEC 27002 and supplements them where necessary, so that they can be effectively used for managing health information security. By implementing ISO 27799:2016, healthcare organizations and other custodians of health information will be able to ensure a minimum requisite level of security that is appropriate to their organization's circumstances and that will maintain the confidentiality, integrity and availability of personal health information in their care. It applies to health information in all its aspects, whatever form the information takes (words and numbers, sound recordings, drawings, video, and medical images), whatever means are used to store it (printing or writing on paper or storage electronically), and whatever means are used to transmit it (by hand, through fax, over computer networks, or by post), as the information is always be appropriately protected. ISO 27799:2016 and ISO/IEC 27002 taken together define what is required in terms of information security in healthcare, they do not define how these requirements are to be met. That is to say, to the fullest extent possible, ISO 27799:2016 is technology-neutral. Neutrality with respect to implementing technologies is an important feature. Security technology is still undergoing rapid development and the pace of that change is now measured in months rather than years. By contrast, while subject to periodic review, International Standards are expected on the whole to remain valid for years. Just as importantly, technological neutrality leaves vendors and service providers free to suggest new or developing technologies that meet the necessary requirements that ISO 27799:2016 describes. As noted in the introduction, familiarity with ISO/IEC 27002 is indispensable to an understanding of ISO 27799:2016. The following areas of information security are outside the scope of ISO 27799:2016: a) methodologies and statistical tests for effective anonymization of personal health information; b) methodologies for pseudonymization of personal health information (see Bibliography for a brief description of a Technical Specification that deals specifically with this topic); c) network quality of service and methods for measuring availability of networks used for health informatics; d) data quality (as distinct from data integrity).