(39) All processing of personal data should be lawful and fair. It should be transparent to individuals that personal data concerning them is being collected, used, viewed or otherwise processed, and to what extent that personal data is or will be processed. The principle of transparency requires that all information and all communications related to the processing of such personal data be easily accessible and understandable, and in clear and simple language. This principle applies in particular to informing data subjects of the identity of the controller and the purposes of the processing and other information designed to ensure that the processing is fair and transparent to the individuals concerned, as well as the right of such individuals to obtain confirmation and information about the personal data processed concerning them. Individuals should be made aware of the risks, principles, safeguards and rights associated with the processing of personal data and how to exercise their rights in connection with such processing. In particular, the specific purposes of personal data processing should be clear, legitimate and defined at the time of collection. Personal data should be adequate, relevant and limited to what is necessary for the purposes for which they are processed. This requires, in particular, ensuring that the data retention period is kept to a strict minimum. Personal data should be processed only in cases where the purpose of the processing cannot be reasonably achieved by other means. To prevent personal data from being kept for longer than necessary, the controller should set a deadline for deletion or periodic review. All reasonable measures should be taken to ensure the rectification or deletion of personal data that is inaccurate. Personal data should be processed in a manner that ensures its adequate security and appropriate confidentiality, including protection against unauthorized access to and use of the data and processing equipment.