crc-cards

How does one elaborate design using CRC cards?

I've always been wondering how people use CRC (class responsiblity collaboration) cards. I've read about them in books, found vague information on the internet, but never grasped it really. I think someone ought to make a youtube video showing a session with CRC cards, since one of my books described it as being very hard to formulate in...

Why do we list collaborators in CRC cards?

In the CRC cards why do we list all the collaborators instead of just dependency. I mean if class A calls functions of B, why is A mentioned in the B class CRC collaborator section. It would be much better if we simply leave A in B's CRC card, as in A's CRC card B is already mentioned. This way we can figure out dependency also from CRC ...