The Gnats Display Team operate under CAA authority and within the regulations defined under CAP 563.
https://www.caa.co.uk/docs/33/CAP%20...20Aircraft.pdf
Covers all facets or links to others that are greater in depth. Certainly covers experience, currency, maintenance, equipment's, organisation, auditing, etc. Even been updated on the fact that it is now legal to cover some costs by passenger payments.