xmlns:atom="http://www.w3.org/2005/Atom"
9A document bearing a certificate which—
(a)is signed by a person authorised in that behalf by the Department; and
(b)states that the document, apart from the certificate, is a record of a decision—
(i)of a Commissioner;
(ii)of a social security appeal tribunal;
(iii)of a disability appeal tribunal; or
(iv)of an adjudication officer,
shall be conclusive evidence of the decision; and a certificate purporting to be so signed shall be deemed to be so signed unless the contrary is proved.