There are a ton of them. A friend recently told me that years ago he worked for a tech firm that was a CIA front. He said everyone in the firm had an alias name at work. So if your real name was David Campbell, your work name was Billy Simms. He said you could only use the alias in the office. He also said if you ran into someone outside of work, that's when it became tricky...which name to use. That's DC for ya.