What does it mean when a cat winks?

Dear Most Esteemed and Knowledgeable Kitties:
OK, this is probably a stupid question, but what does it mean when a cat winks? I read somewhere that it means something.
~Barb
Siouxsie: Let us start by assuring you that there’s no such thing as a stupid question, Barb.
Thomas: In fact, we think it’s highly commendable that you want [...]