[New York, October 29. Image via Bauer-Griffin.]
@BiscuitDoughJones: Confraternity of Christian Doctrine. When kids who are Catholic don't go to Catholic schools (and, thus, don't spend hours learning Catholic doctrine) they get to go to CCD classes outside of their heathen public school class.
I think Rome came up with CCD so it's only the Catholics who call it this. The rest of y'all call it "Sunday School".