So I stumbled on this guy's youtube video channel and he's a very sharp engineer. Although some of his vid's are long in the tooth, I thought this one was one of the more interesting ones. I had never considered this in capacitor placement (polarity) in circuit design.

https://www.youtube.com/watch?v=BnR_DLd1PDI

Tom (PK)

Take a look at the old black plastic cylindrical Aerovox brand film caps from waaay back. They're non-polarized, but they still have a band on them to indicate which of the two leads is connected to the outside foil. I wouldn't call it "polarized" or "polarity sensitive" but when you need all the interference rejection (or RFI suppression!) you can get, it can make a difference.