I can't say if these codes are that important in IMCDb. After all, we can put them in comments too, in this v2. The most important is that all cars should be identified the same way...
All I know is that I like to "play" with that concept of plateform since almost 30 years: it's funny to try to tell the differences between the siblings of a same plateform, or to find (more or less) hidden siblings.