There were some intriguing nuggets - for instance, Harold Wilson's Labour government contemplating prosecuting Peter Hain, now a Foreign Office minister, for conspiracy over his campaign to stop a tour by the South African cricket team, and MI5's secret contacts with the former dockers' leader, Brian Nicholson. Yet many are utterly banal. The answer is that what papers are released, and when, is decided almost entirely arbitrarily by unaccountable officials in the historical records sections of Whitehall departments. They weed as well as select. But there is more.
Absolute discretion is the name of the game.
Despite official rules that once a file has been shown to one person, it should be available to all, Whitehall, and notably security and intelligence agencies, gives privileged access to documents to approved writers. And despite strict rules covering the preservation of documents, some have been destroyed. Sir Edward Heath, chief whip at the time, revealed in his memoirs two years ago that Sir Anthony Eden ordered the destruction of his copy of the secret plan to invade Egypt agreed with France and Israel during the 1956 Suez crisis. This writer has been told by a cabinet office source that papers on the 1985 Westland crisis have also been destroyed. The PRO is a precious resource under its keeper, Sarah Tyacke.