16.—(1) Competent authorities may require that a declaration under regulation 15 be accompanied by the documents in paragraph (2)—
(a)for the first provision of services, or
(b)if there is a material change in the situation substantiated by the documents.
(2) The documents that may be required are—
(a)proof of nationality of the applicant or, where the applicant is not a national of a relevant European State, proof of the Union right on which the applicant relies;
(b)an attestation certifying that the applicant is legally established in another relevant European State for the purpose of pursuing the activities concerned and that the applicant is not prohibited from practising, even temporarily, at the moment of delivering the attestation;
(c)evidence of professional qualifications;
(d)for cases referred to in regulation 8(3)(e), any means of proof that the applicant has pursued the activity concerned for at least one year during the previous ten years;
(e)for professions in the security sector, in the health sector and professions related to the education of minors, including in childcare and early childhood education where required for United Kingdom professionals, an attestation confirming the absence of temporary or final suspensions from exercising the profession or of criminal convictions;
(f)for professions that have patient safety implications, a declaration about the applicant's knowledge of the language necessary for practising the profession in the host State;
(g)for professionals covering the activities referred to in regulation 35 and which were notified to the Commission as requiring a prior check of qualifications under regulation 19, a certificate concerning the nature and duration of the activity issued by the competent authority or body of the home State.