Hi Christian, thanks for the quick and comprehensive reply! I wrote a little repository for finding non-BIDS-conform NIFTI-files in a directory (it simply just crawls through the folder and looks for files that match the CAT12-prefix or any other prefix). This can be used as a workaround until CAT12 & SPM12 might eventually become BIDS-conform in the future. I will close this thread for now and mark your answer as solution. Looking forward for BIDS-standard in SPM12 and CAT12!