It would seem that you cannot CP DISC HOLD from a VTAM session, because some
smart ass has decided that it's easier  to say "INVALID OPTION" than to ignore
the option. So, 1.5l  will probably complain if you try a  DISC command from a
VTAM terminal.  Use CP DISC instead.  1.5m will do a  CP DISC HOLD *and*  a CP
DISC, with a DIAG(8,..) so as to suppress the stupid error message.
 
  Eric