For those countries where national legislation provides an exemption by means of a  reimbursement, the amount of VAT must be shown separately. In case of doubt about the  applicable VAT system, it is the tenderer's responsibility to contact his or her national  authorities to clarify the way in which the European Union is exempt from VAT.  4.3. Signature policy: how can documents be signed?  4.4. Confidentiality of tenders: what information and under what conditions can be  disclosed?  Where a document needs to be signed, the signature must be either hand-written or a qualified  electronic signature as defined in Regulation (EU) No 910/2014 on electronic identification  and trust services for electronic transactions in the internal market (the  eIDAS Regulation ).  For hand-written signatures see Section 1 of the Invitation to tender.  For electronic signatures see: https://webgate.ec.europa.eu/fpfis/wikis/x/YIrgIw  All documents must be signed by the signatories (when they are individuals) or by their duly  authorised representatives.  For the following documents, when signed by representatives, tenderers must provide  evidence for the delegation of the authorisation to sign:  - The Declaration on Honour of the tenderer (in case of joint tender – the Declarations  on Honour of all group members);  - (If applicable – in the case of joint tender) the power(s) of attorney drawn up using the  model attached in  Annex 3 ).  The delegation of the authorisation to sign on behalf of the signatories (including, in the case  of proxy(-ies), the chain of authorisations) must be evidenced by appropriate written evidence  (copy of the notice of appointment of the persons authorised to represent the legal entity in  signing contracts (together or alone), or a copy of the publication of such appointment if the  legislation which applies to signatory requires such publication or a power of attorney). A  document that the Contracting authority can access on a national database free of charge does  not need to be submitted if the Contracting authority is provided with the exact internet link  and, if applicable, the necessary identification data to retrieve the document.  Once the  Contracting authority has opened a tender, it becomes its property and shall be  treated confidentially, subject to the following:   For the purposes of evaluating the tender and, if applicable, implementing the  contract, performing audits, benchmarking, etc., the  Contracting authority  is entitled  to make available (any part of) the tender to its staff and the staff of other Union  institutions, agencies and bodies, as well to other persons and entities working for the  Contracting authority  or cooperating with it, including contractors or subcontractors  and their staff provided that they are bound by an obligation of confidentiality.   After the signature of the award decision tenderers whose tenders were received in  accordance with the submission modalities, who have access to procurement, who are  not found to be in an exclusion situation referred to in Article 136(1) of the FR, who  26