BBC Radio 4 One of the great unwritten laws of radio scheduling is that you can’t go wrong with royal protocol. The producer who, this time last year, reassembled five out of the six aristocratic “gels” who had attended the 1953 Coronation and invited them to recall the frightfully good time they had had, knew exactly what he, or she, was doing, and so did the commissioning editor who decided to sponsor the Labour MP Janet Anderson’s account of time in the little-known post of vice chamberlain of the Royal Household (2 May).And what duties does the position entail? Why, as well as allowing oneself to follow an archaic ritual of being held hostage at the palace on the day of the Queen’s Speech, it involves the government whip so honoured in filing a budget of