While working with Exiftool I find that the order of tags in CR2 file may change. I look on some "offset" tags, such as "Preview Image Start", "Thumbnail Offset", "Strip Offsets". For instance when I change thumbnail image or/and preview image - they may change their places. Before changing the order was: thumbnail, preview, raw data; after change: thumbnail, raw, preview. Of course I change the lenght of this tags and the next tag starts accordingly with shift. But why they change their sequence?
Sometimes between raw and preview images there is any information (some kilobytes between preview ends and raw starts), and after change this information moves somewhere (the gap between end and start becomes zero).
In all cases after change CR2 files works well - I don't find any troubles.
The question is: is the order of tags important, or such changes are not critical?