Carlos Ramirez is a graduate student in sociology. He's part of Dr. Speers project to collect data for his thesis. He's studying difficulties and breakdowns in communication between high technologists and the common manager.
One of the questions that interests him is exactly when a gadgeteer or devisor shifts from understandable speech to impenetrable jargon.
Chester nicknamed him "Number 5" because he was the fifth assistant that Dr. Speers had introduced him to. The nickname stuck.
He appears to be a baseline.