The CAA publications below were applicable in 2015. Both publications have since been amended and new editions published.
CAP 1047 - Civil Air Displays, A Guide for Pilots:
http://publicapps.caa.co.uk/docs/33/...r%20pilots.pdf
CAP 403 - Flying Displays and Special Events: A Guide to Safety and Administrative Arrangements:
http://www.acro.co.uk/files/CAP403.pdf
Chapter 6 - Pilot Display Competency
2.4.6. DAEs [Display Authorization Evaluators] should actively monitor Display Pilot standards throughout the display season.
8.6 Minimum Heights During Displays
8.6.1 - All aerobatic maneuvers, including inverted flypasts and maneuvers which involve pulling through the vertical are to be executed above the approved aerobatic display height.