I think we want to allow the length to be < 12.  It should be ok to stop listing aberrations at coma for instance.  Eventually we want to allow the length to be > 12 as well, so we'll definitely want to allow variable sizing then.  But for now we should just check that it is <= 12.

Also, since we are ignoring the first 4, it might be worth issuing a warning (at least -- maybe even an error) if any of the first 4 values are not == 0.