> No Chinaman must figure in the story. (The "No Chinaman rule" was a reaction to, and criticism of, racial cliches prevalent in 1920s English writing. Knox explained, "I see no reason in the nature of things why a Chinaman should spoil a detective story. But as a matter of fact, if you are turning over the pages of an unknown romance in a bookstore, and come across some mention of the narrow, slit-like eyes of Chin Loo, avoid that story; it is bad.")
I quote it not to endorse it, but for a better feel for how they thought