What is an Intel C33389 Reference Fastener?

You know those little black and white plastic push-to-click feet that accompany every Intel processor heatsink made for socket LGA775, LGA1156 and LGA1366? They look like this (below) and fit into the four small holes in the motherboard around the CPU socket, whereby a bit of downward force locks them and the heatsink in place. Well, we've been wondering for years what the proper name for these clips is, particularly as Frostytech spills a lot of pixels talking about different Intel heatsink retention/mounting bracket systems.