What, exactly, is a Class E Personnel? I've seen references, but the only definition i can get is "Ask Again Later". Along the same vein, whatever happened to Class A-C?
"E: Temporarily affixed to the start of a security clearance (e.g. E1), this is used when a new SCP object has been discovered but is still in an unsecured or uncontrolled state. E-clearance personnel are tasked with bringing the SCP into effect and maintaining it. Once the SCP are in place and the object is secure, the E is removed and the personnel are given the appropriate number on the end of their clearance."
I would assume that it's Class D because Class A, B, and C has connotations of actual importance. Class D? Nobody gives a shit about you.