Only Known by Their Nickname/Quotes

Karrde: We haven't yet been able to decipher the message, but it definitely contained Thrawn's name. His full name, not just the core name 'Thrawn.'

Han Solo: I didn't even know he had more name.

Karrde: Most people don't.

—Specter of the Past

We're the thin/fat gay married Anglican Marines. Why would we need names as well?

—The Fat One, Doctor Who, "A Good Man Goes to War"

"My nickname's Boss! Even the author doesn't know my real name!"

—Boss, Shin Mazinger Shougeki! Z-hen

"THE CAPTAIN! HIS NAME IS THE CAPTAIN!"

—Nextwave theme song.