Clef is well known for efficient terminations of dangerous SCPs, as well as his eccentric personality, hat, and ukulele.
The genre-savvy and enigmatic "Dr. Alto Clef" maintains that his true name is that of an A major chord played on a ukelele, which he carries around with him at all times should other entities wish to address him by name. He has received his current nickname due to his habit of signing reports with a hand-drawn Alto Clef symbol.