With all the success of BN, it is amazing and disappointing at the same time that there are so many fantastic results but so little practical advice, how to actually implement the whole pipeline. No doubt, BN can be implemented pretty easy in the training part of the network, but that is not the whole story. Furthermore, there are, at least, two ways to use BN during training. First, with a running average for mean/std values per layer which can later be used for unseen data. Second, to calculate the mean/std values for each mini-batch and then run a separate step to fix the statistics for the data at the end of the training.