Yes, it's true. The safety guidelines for all volunteer staff now state that "sensible" footwear must be worn on the "working floor" at all times that the festival is open to the public. Any footwear which has an open toe or high heels is unsuitable. Volunteers who present themselves wearing such footwear may not be permitted to work in these areas and may be re-deployed elsewhere.
And that does not mean redeployment to the GBBF Press Office as we have banned sandals for years - though more for PR and aesthetic reasons than health and safety.
For the avoidance of doubt, all customers ARE permitted to wear their sandals and high heels. Socks, shorts, fleeces, anoraks, beery T-shirts, silly hats, panda-pop bottles, beards and bellies are also most welcome.