A socket architecture that ensures that the correct modules and plugs are inserted. For example, RAM modules are keyed with notches in the row of pins. The distinction between a keyed architecture and an entirely different type of plug and socket is that keyed connections are rather subtle and sometimes only obvious when trying to insert the plug. See plugs and sockets.


Keyed RAM Modules

The incorrect DDR generation cannot be inserted into the memory slot because the notch will be in the wrong place. See memory module.
