11In any proceedings, a certificate—
(a)that payment of a fixed penalty was, or was not, received by the relevant officer specified in the fixed penalty notice by a date specified in the certificate, or
(b)that a letter containing an amount sent by post in payment of a fixed penalty was marked as posted on a date specified in the certificate,
shall, if the certificate purports to be signed by that officer, be evidence (and in Scotland sufficient evidence) of the facts stated.