Notes to detail some QUALITY bits.

Note that the bit assignments for lev1.5 and above for records with no actual data
present (QUALITY < 0) may overlap with bits for cases where QUALITY > 0. 
When interpreting QUALITY bits be sure to note which section of QUALITY.txt applies.

In cases where 45s or 720s data exists and there is a code error detected
we will set bit 0x80 for existing records while they are waiting replacement
with reprocesed data.  the cases where this has happened include:
  1.  Sept 2017.  for CALVER64 masked with 0xF0000 leaves 0x20000 for the initial
      year+ of modL data, we set QUALITY 0x80 while waiting for reprocessing
      of hmi.S_720s and all of its derived products.  The records with this
      QUALITY bit set should not be visible once the reprocessing is done.
      It is expected to take several months.