I think I've read somewhere speculation as to whether Sayers wrote, or had a hand in, the Detection Club's oath (reprinted at
http://www.sfu.ca/english/Gillies/Engl38301/oath.htm). I have found confirmation of this in a letter by Anthony Berkeley, the Club's founder, dated 1 May 1931, in the G.K. Chesterton papers at the British Library. Berkeley, inviting Chesterton to attend a meeting, wrote:
"...a new member, Miss Helen Simpson, is to be initiated that evening in due form as laid down in a most ceremonious ritual drawn up by Miss Dorothy Sayers, whereby most solemn pledges are required touching the art and honour of detective fiction, which I think may be amusing."
