And I made up the HTTP status code "397 Tolerating" so that if you spell it "Referrer", browsers can correct you while still giving you the response you wanted :-p (see section 3 example):
So am I! I did it as an April Fool’s joke (see the date and the author, Ben Dover). But I also think it would be legitimately useful and have long wished for a standard protocol for expressing that you’re “tolerating” a standards violation while still pointing it out.