His aide was pulling him in another direction and I sensed this would be the final question, so I asked if anyone in the Pentagon calls him ‘Mad Dog.” He paused and said:
You know, that is not my real call sign? That was something made up by the press. Some reporter, who needed a quick name for me. My real name is Chaos. “Colonel Has An Outstanding Solution.” That is my real call sign and what my men used to call me. Anyone who has ever worked with me calls me Chaos. That’s the name I prefer.
I stood there, shellshocked from Mattis’s response. The Secretary of Defense leaned in toward me and said, “Call me Chaos,” winked, and walked away.http://www.weaselzippers.us/327804-secretary-of-defense-james-mattis-call-me-chaos/