Grouping

The grouping feature allows meta-data information found from one file to be used in renaming other files that have the same filename prefix. Note that in order for this to work, the source of the meta data information must be the first one scanned in the group. This can only be done if the source file is alphabetically first. e.g. If you have the files 'abc.jpg' and 'abc.nef', then the grouping function will take the image information from the jpg file and insert it simultaneously into the abc.jpg and abc.nef filenames.

If the filenames were abc.crw and abc.jpg, then the grouping will not work because abc.jpg is alphabetically after abc.crw and will be scanned first. Since the .crw is scanned first and meta data cannot be read from the crw file, none of the files in the group will have any meta-data inserted into their filenames. One simple work-around for this case is to scan anyway, then resort the 'old names' in the preview list in reverse order. This should position all the .jpg files before the equivalent .crw files. Then press the rescan button and the grouping will work.
if resorting by column does not provide the desired order, then you can either resort manually or you could first rename the files that are the src of the meta-data to something with say .aaa extensions. Then run PFrank again using the grouping (in which case you can then also change the .aaa suffix back to the original suffix).