Political briefings: Letwin, Major, Huhne and Hutton
2 April 2014 Last updated at 12:15 BST
Sometimes politicians mean to brief the press with an off-the-record comment, but at other times it can get a bit out of hand.
Last weekend, an unnamed government minister told a reporter that an independent Scotland might be able to use the pound after all, leading to a hunt to name the person behind the quote.
Giles Dilnot reports in a Daily Politics film, with the help of BBC archive.