068  NLM Classification Number Assigned in Canada  [obsolete, 1997]  [CAN/MARC only]:

Field 068 was made obsolete in 1997.  The first indicator was undefined.  The second indicator was defined to indicate source of the number (0 = NLM classification number assigned by LAC and 1 = NLM classification number assigned by the contributing library).  The subfield codes were:  $a (NLM classification number - single number or beginning number of a range), $b (NLM classification number - end number of a range), $c (Explanatory term), and $5 (Library to which class number applies).