It's an idiom, though I don't know how common it is. I've heard it before, but not at all often. https://websites.umich.edu/~jlawler/aue/sig.html https://websi

It's an idiom, though I don't know how common it is. I've heard it before, but not at all often. https://websites.umich.edu/~jlawler/aue/sig.html https://websites.umich.edu/~jlawler/aue/sig.html