Something I overheard this morning got me wondering...

Have any of you been around long enough to know why a diode would have a
designator of CR? What does the CR mean?

What does the U mean on an Integrated Circuit?

Is the K on relays arbitrary since R is used by resistors?

Does anyone really use P anymore for plugs?
(everything I've seen lately is J on connectors, no matter if it is a socket
or a plug)

What do you use for submodules or subassemblies?

Not really important, I was just curious....

Jack