W151 or E151? I don't think it's out of the question to say that if you're specifying more than one of these, you have an error you need to fix, because the behaviour will be unpredictable. This would only be a warning if the app can continue to operate. Strictly, this is true - after all, you *can* specify all three - but you really shouldn't. Having this as W151 says "You can do this if you want to, but we suggest you don't", rather than "No, Don't do this".