Thank you both for your explanations of Baptism and the Catholic Church.
The little knowledge I have on this particular subject is because my wife's relative is soon marrying a Japanese agnostic :), so we had the run-around on what can be done or not.
In this modern day and age, of course people from different faiths marry -- I personally have cousins who have been married for decades to those from not only various Christian denominations but also one to a Hindu. In all of these cases, the pre-marital course helped -- it also helped my wife and me and I strongly recommend it even to non-Catholics
It's simple -- just a bunch of questions to the couple so they both know what each wants.