John,

We may be in agreement after all. Since the ultimate goal of normalization is to eliminate redundancy of data through the concept of "the key, the whole key and nothing but the key" then perhaps there are situations where there may be multiple candidate keys but BCNF isn't techincally necessary for the elimination of redundancies. However, I would propose that the "best practise" would be to apply BCNF whenever there is more than one candidate.