From CAP403:
5.33 In addition to a valid Certificate of Test and Competence, a Display Pilot is required to meet certain recency requirements before his DA is valid. In the 90 days preceding a demonstration at a flying display for which an Article 162 Permission is required, a minimum of three full display sequences must have been flown or practised, with at least one display sequence flown or practised in the specific type of aircraft to be displayed.
5.34 A log book entry is sufficient proof that the display sequences or practices have been flown.