d) describe the measures taken or proposed to be taken by the data controller to address the personal data breach, including any measures to mitigate its possible adverse effects; and e) in the case of a communication made to affected data subjects or a public communication, provide advice about measures the affected data subject could take to mitigate effectively the possible adverse effects of the personal data breach. 2. To the extent that it is not possible to provide information under this article at the same time, the information may be provided in phases without undue further delay. Article 27: Records of data breaches 1. Each data controller shall keep a record of all personal data breaches with respect to personal data processed by it, including the facts relating to the personal data breach, its effects and the remedial action taken in a manner that enables the Authority to verify compliance with this Chapter. Article 28: Guidance from the Authority 1. The Authority shall issue guidance on the steps to be taken by data controllers to comply with the personal data breach notification and communication obligations in this Chapter. Article 29: Data protection impact assessments 1. Where processing by a data controller of major importance is likely to result in high risk to the rights and freedoms of a data subject by virtue of its nature, scope, context and purposes, a data controller of major importance shall: a) carry out a data protection impact assessment prior to the processing; and b) submit a data impact assessment report to the Authority prior to the processing. 2. The data controller of major importance shall consult the Authority prior to the processing if, notwithstanding the measures envisaged under sub-article 4d), the data protection impact assessment indicates that the processing would result in a high risk to the rights and freedoms of a data subject. 3. The Authority shall issue guidelines on: a) carrying out data impact assessments; and b) the kinds of processing which require a data protection impact assessment pursuant to sub-article 1. 21