I was basing my comment on this;
Minimum Heights By Day
Although SERA changes the minimum height to a blanket 500 ft above the surface, the CAA has used the flexibility provided in SERA to allow aircraft in the UK to fly below 500 ft provided they are 500 ft away from persons, vessels, vehicles and structures – in other words no change from the UK’s former '500ft Rule' that people flying in the UK are used to applying. The CAA has also granted generic permissions to allow for all the long-standing exceptions to the old rule 5 that were contained in rule 6 – i.e. gliders hill-soaring, aircraft picking-up and dropping articles at aerodromes, practising forced landings and flying displays/air races/contests, to continue unaffected. Otherwise 1000 ft is the minimum height over cities, towns or settlements or over an open-air assembly of persons above the highest obstacle within a radius of 600 m from the aircraft.
Which comes from the CAA website - of course that in itself does not necessarily make it true!!!!! It is however a lot more understandable than the ORS....... When is the highway code of the air going to be published? That might bring these threads to an end!