b) For a natural person pursuing business, the trading company or the name including a differentiating amendment or other designation, registered office address and identification number of the person c) For a public authority, its name, registered office address, identification number of a person, if assigned, or an identifier of the public authority if an identification number was not assigned Also including information about a natural person that is entitled to act on behalf of the public authority or the legal or natural person specified in Section 3 in issues governed by this act, i.e. his/her name, surname, phone number and email address. (2) Contact details and their changes shall be announced by: a) Public authorities and legal or natural persons specified in Section 3, letters a), b) and h) to the operator of the national CERT b) Public authorities and legal or natural persons specified in Section 3, letters c) to g) to the Agency. (3) Public authorities and legal or natural persons specified in Section 3, letters c) to g) shall immediately announce only changes to the details specified in paragraph 1, which are not referential details kept in basic registers. (4) The Agency shall keep a contact details record containing details specified in paragraph 1. (5) The Agency is entitled to request contact details collected by the operator of the national CERT according to paragraph 2, letter a) under the state of cyber emergency. (6) The Agency is furthermore entitled to request the contact details of public authorities and legal or natural persons specified in Section 3, letter h) collected by the operator of the national CERT for the purpose of their inspection. (7) The template for contact details notice and its form shall be established by the implementing legal regulation. Section 17 The national CERT (1) The national CERT ensures the sharing of information on the national and international level in the field of cyber security under the provisions of this Act. (2) The operator of the national CERT: a) Receives notices about contact details from public authorities and legal or natural persons specified in Section 3, letter a), b) and h); keeps a record of them and stores them b) Receives cyber security incident reports from public authorities and legal or natural persons specified in Section 3, letters b) and h); keeps a record of them, stores and protects them c) Evaluates cyber security incidents of public authorities and legal or natural persons specified in Section 3, letters b) and h) d) Provides public authorities and legal or natural persons specified in Section 3, letters a), b) and h) with methodical support, help and cooperation when a cyber security incident occurs