http://www.hertsmere.gov.uk/business/licensing/alcoholentertainmentlicensing/dnld_alcoholentertainmentlicensing/Premise_licenses

John King comments:
Hertsmere Council don't approve of children listening to music. Here they are banning children (in Hertfordshire that means under-18s) from a premises during live music events. They are allowed on the premises at all other times.

Children being prevented from going to their own school - interesting concept.