By supplying a blank parameter name, all currently active NDF parameters can be cancelled in a single call. However, it is possible to exclude selected parameters from this automatic cancellation if necessary. To do this, the parameter to be excluded should be marked by making a prior call to this routine with an asterisk appended to the end of the parameter name. Any subsequent call to this routine with a blank parameter name will skip such marked parameters. To mark all currently active NDF parameters in this way, supply the PARAM argument holding just an asterisk.
When cancelling a parameter, the behaviour of this routine is identical to PAR_CANCL.
Any remaining NDF identifiers for the associated NDF are unaffected by this routine. It
only affect is to cause NDF_ASSOC or NDF_EXIST to prompt for a new NDF when called
This routine attempts to execute even if STATUS is set on entry, although no further error report will be made if it subsequently fails under these circumstances.